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    Stroke is one of the leading causes of death and disability worldwide and in the United States, specifically. New research finds that excessive sleep considerably raises the risk of this cardiovascular problem.

    Globally, 15 millionTrusted Source people experience a stroke each year. Almost 6 million of these people die as a result, and 5 million go on to live with a disability.

    In the U.S., over 795,000Trusted Source people have a stroke each year.

    The list of traditional risk factorsTrusted Source for stroke is long, ranging from elements of lifestyle, including smoking, to preexisting conditions, such as diabetes.

    More recently, researchers have started exploring sleep duration as another potential risk factor. Some studiesTrusted Source have found that either too much or too little sleep can increase the risk of cardiovascular events, including stroke.

    According to these findings, regular sleep deprivation and sleep for more than 7 hours per night are each associated with a higher risk of stroke.

    Now, a study appearing in the journal Neurology finds an association between daytime naps, excessive sleep, and stroke risk.

    Dr. Xiaomin Zhang, from Huazhong University of Science and Technology, in Wuhan, China, is the corresponding author of the paper that details this study.

    85% higher risk in long sleepers, nappers

    Dr. Zhang and the team collected information from 31,750 people in China. None of the participants — who were 62 years old, on average — had a history of stroke or any other serious health condition at the start of the study.

    The participants answered questions about their sleeping patterns and napping habits, and the researchers clinically followed the group for an average of 6 years.

    The team found that 8% of the participants were in the habit of taking naps that lasted longer than 90 minutes, and 24% reported sleeping for at least 9 hours each night.

    Over the study period, there were 1,557 strokes among the participants. Those who slept for 9 or more hours per night were 23% more likely to experience a stroke than those who regularly slept only 7–8 hours each night.

    People who got less than 7 hours of shuteye or 8–9 hours had no higher risk of stroke than those who slept 7–8 hours.

    Importantly, people who both slept for longer than 9 hours and napped for more than 90 minutes per day had an 85% higher risk of stroke than those who slept and napped moderately.

    Finally, sleep quality seemed to play a role — people who reported poor sleep quality were 29% more likely to have a stroke than those whose sleep quality was reportedly good.

    These results continued to be significant after adjusting for potential confounders, such as hypertension, diabetes, and smoking.

    “These results highlight the importance of moderate napping and sleeping duration and maintaining good sleep quality, especially in middle-age and older adults.”

    Dr. Xiaomin Zhang

    Study limitations and potential mechanisms

    The researchers acknowledge some limitations to their work, as well as the fact that more research is necessary.

    First, because the study was observational, it cannot prove causality. Second, the research did not account for sleep apnea or other sleep disorders that may have influenced the results.

    Third, self-reported data is not as reliable as data recorded by researchers who observe participants’ sleep.

    Finally, the results may only apply to older, healthy Chinese adults and not to other populations.

    “More research is needed to understand how taking long naps and sleeping longer hours at night may be tied to an increased risk of stroke, but previous studies have shown that long nappers and sleepers have unfavorable changes in their cholesterol levels and increased waist circumferences, both of which are risk factors for stroke,” explains Dr. Zhang.

    “In addition, long napping and sleeping may suggest an overall inactive lifestyle, which is also related to increased risk of stroke.”

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      Neck tension refers to neck pain that develops when the muscles in the neck cannot relax, which can lead to soreness, muscle spasms, and headaches. It has numerous possible causes, ranging from joint problems to inflamed nerves.

      Depending on the underlying cause, people can experience different types of neck tension and pain, which distinct symptoms can accompany. Research suggests that as many as 71% of adultsTrusted Source around the world will experience neck pain at some point in their lifetime.

      Continue reading this article to learn more about the causes, symptoms, and treatment of neck tension.


      The brain sends electrical signals, or nerve impulses, to trigger muscle movement. Muscles can either contract or relax, depending on the message that they receive from the brain.

      Muscle tension occurs when a muscle stays contracted despite receiving signals from the brain that tell it to relax. If a muscle remains contracted for too long, it can cause pain.

      People can develop neck tension for numerous reasons. Common causes of neck tension include:

      Poor posture

      Poor posture can affect the neck muscles. People who find themselves hunching over their computer or slouching in their chair all day may notice some neck tension after a while.

      The authors of a 2016 studyTrusted Source involving 126 college students found a correlation between a forward head position and increased neck pain and disability.

      Poor posture can cause the weight of the head to shift forward and away from the center of the body, forcing the neck muscles to work harder to support the head.

      Hunching over a computer or looking down at a phone not only moves the head forward but also forces the neck to bend with it. This bending can overextend the muscles in the back of the neck, resulting in pain and inflammation.

      Sleeping in the wrong position

      Posture affects the body at all times, even during sleep. People who sleep on their stomachs tend to rest one side of their face on the pillow. Doing this can overextend the muscles on that side of the neck.

      Sleeping with large pillows can elevate the head too high, forcing the neck to bend forward. Staying in this position throughout the night may result in neck tension the following morning.

      Repetitive neck movements

      People who perform repetitive movements throughout the day can develop repetitive motion disorders.

      While these disorders usually occur in the hands, wrists, and shoulders, they can also affect the neck, according to the National Institute of Neurological Disorders and Stroke.

      Without treatment, repetitive motion disorders can lead to pain, swelling, and even permanent tissue damage.

      Teeth grinding

      Bruxism is a condition in which people grind or clench their teeth while they sleep. Grinding or clenching the teeth puts pressure on the muscles in the jaw and neck, which can cause neck tension, pain, and headaches.


      A person can injure the muscles in their neck if they lift heavy weights, play impact sports, or experience whiplash from a car accident.

      These types of injuries can cause mild-to-severe muscle strains, which may require medical treatment or physical therapy.

      Untreated muscle strains can lead to persistent neck pain and even permanent damage that reduces the range of motion and flexibility in the neck.


      Stress has a powerful effect on the entire body. When the brain senses stress, it signals the release of several hormones, such as cortisol and epinephrine. These hormones increase the heart rate and blood pressure, as well as tightening the muscles.

      When a person experiences stress regularly, their muscles remain tense and contracted for longer periods, which can result in neck and shoulder tension.

      According to a 2017 study involving 148 people with migraine, nearly 67% of the participants also experienced tension-type headaches and neck pain.

      These individuals also reported higher levels of stress, engaged in less physical activity, and rated their health poorly in comparison with the participants who had migraine without tension headaches and neck pain.


      The symptoms of neck tension can vary in their severity but typically include:

      • muscle stiffness or soreness
      • muscle spasms
      • sharp or intense pain that worsens with movement


      Stretching helps improve flexibility and range of motion, while exercising increases muscle strength. Improving muscle flexibility and strength can help support proper posture and relieve neck tension. People may find the following stretches and exercises beneficial in preventing or relieving neck tension:

      Basic neck stretch

      To perform a basic neck stretch, people can follow these steps:

      • Sit or stand up straight with the neck in a neutral position and the arms and shoulders relaxed.
      • Reach the right hand over the head, placing the palm on the left side of the head.
      • Stretch the left side of the neck by gently pulling the head over to the right.
      • Hold this stretch for 30 seconds and then repeat on the other side.

      Neck rolls

      Neck rolls involve the following series of movements:

      • Begin with the head in a neutral position.
      • Drop the chin toward the chest.
      • Slowly roll the head to one side so that the ear almost touches the shoulder.
      • Continue rolling the head in the same direction, allowing the top of the head to face backward.
      • Bring the head around to the other shoulder.
      • Complete a full rotation by bringing the head to the front of the body, keeping the chin tucked into the chest.
      • Do 5–10 neck rolls in one direction and then repeat the exercise going in the opposite direction.

      Forward neck stretch

      This simple stretch may help relieve tension:

      • Sit or stand with a straight back, keeping the shoulders and arms relaxed.
      • Interlace the fingers and place the palms on the back of the head with the elbows facing forward.
      • Gently pull the head down toward the chest.
      • Hold this stretch for 30 seconds.

      Side-to-side neck exercise

      People can perform this exercise as follows:

      • Sit upright with the shoulders back and the head and neck in a neutral position.
      • Slowly rotate the head from side to side, keeping the chin parallel to the ground.
      • Keep the rotations small to avoid overextending the neck muscles.
      • Complete 5–10 rotations on each side.

      Shoulder blade squeeze

      A shoulder blade squeeze requires a person to follow the steps below:

      • Stand up straight and spread the feet apart.
      • Start with the shoulders in a relaxed position.
      • Squeeze the shoulder blades together behind the body.
      • Hold for 5 seconds.
      • Repeat this exercise 5–10 times.

      Standing pushups

      People can follow these steps to do a standing pushup:

      • Stand about an arm’s length away from a wall with the feet spread apart.
      • Place the hands on the wall, making sure that they align with the shoulders.
      • Keeping the back straight, slowly bend the elbows, bringing the upper body toward the wall.
      • Straighten the elbows and return to the starting position.
      • Repeat this exercise 5–10 times.


      In addition to the stretches and exercises above, people can relieve neck tension with rest, over-the-counter (OTC) medications, and lifestyle changes.

      The following remedies may help people manage neck tension:

      • applying a cold compress to reduce pain and inflammation
      • applying a warm compress to help relax tense neck muscles
      • taking OTC pain relievers to reduce mild-to-moderate muscle pain
      • taking an Epsom salt bath
      • practicing stress management and relaxation techniques, such as meditation and yoga
      • exercising regularly
      • getting a massage
      • changing sleeping positions and using pillows that support the neck without overextending it

      When to see a doctor

      People may wish to see a doctor if they experience persistent neck tension that does not improve with at-home exercises and remedies.

      People may require immediate medical attention if they develop neck pain after an injury or a car accident or if they experience the following symptoms:

      • intense or sharp neck pain
      • recurring headaches
      • fever
      • nausea
      • vomiting

      People who grind or clench their teeth at night can speak with a dentist about getting a bite guard to wear at night.


      Neck pain is a common complaint that affects people all around the world. Muscle tension is a common cause of neck pain and can develop as a result of poor posture, repetitive movements, and injuries, among other factors.

      People can relieve neck tension by stretching the neck muscles, which improves flexibility and range of motion. Exercises that target the muscles in the back, shoulders, and neck can help improve a person’s posture and prevent neck tension.

      People who experience neck tension that interferes with their ability to function normally may wish to consider speaking with a doctor about medical treatment options.

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        As the use of marijuana is increasing in the United States, researchers are asking whether the use of this substance — particularly smoking joints — is associated with an increased risk of any form of cancer, and, if so, which.

        Marijuana is one of the most widely used drugs in the United States, with more than one in seven adults reporting that they used marijuana in 2017.

        Statistical reports project that sales of cannabis for recreational purposes in the U.S. will amount to $11,670 million between 2014 and 2020.

        According to recent researchTrusted Source, smoking a joint remains one of the main ways in which individuals use marijuana recreationally.

        While specialists already know that smoking tobacco cigarettes is a top risk factor for many forms of cancer, it remains unclear whether smoking marijuana can increase cancer risk in a similar way.

        To try to find out whether there is a link between recreational marijuana use and cancer, researchers from the Northern California Institute of Research and Education in San Francisco and other collaborating institutions recently conducted a systematic review and meta-analysis of studies assessing this potential association.

        In their paper — which appears in JAMA Network OpenTrusted Source — the team notes that marijuana joints and tobacco cigarettes share many of the same potentially carcinogenic substances.

        “Marijuana smoke and tobacco smoke share carcinogens, including toxic gases, reactive oxygen species, and polycyclic aromatic hydrocarbons, such as benzo[alpha]pyrene and phenols, which are 20 times higher in unfiltered marijuana than in cigarette smoke,” write first author Dr. Mehrnaz Ghasemiesfe and colleagues.

        “Given that cancer is the second leading cause of death in the United States and smoking remains the largest preventable cause of cancer death (responsible for 28.6% of all cancer deaths in 2014), similar toxic effects of marijuana smoke and tobacco smoke may have important health implications,” they go on to emphasize.

        ‘Misinformation — a threat to public health’

        Dr. Ghasemiesfe and team identified 25 studies assessing the link between marijuana use and the risk of developing different forms of cancer. More specifically, eight of these studies focused on lung cancer, nine looked at head and neck cancers, seven examined urogenital cancers, and four covered various other forms of cancer.

        The studies found associations of different strengths between long-term marijuana use and various forms of cancer.

        The researchers note that the study results regarding the link between marijuana lung cancer risk were mixed — so much so that they were unable to pool the data.

        For head and neck cancer, the researchers concluded that “ever use,” which they define as exposure equivalent to smoking one joint a day for 1 year, did not appear to increase the risk, although the strength of the evidence was low. However, the studies produced mixed findings for heavier users.

        There was insufficient evidence to link this drug to a heightened risk of nasopharyngeal carcinoma, oral cancer, or laryngeal, pharyngeal, and esophageal cancers.

        Among urogenital cancers, the investigators found that individuals who had used marijuana for more than 10 years appeared to have a higher risk of testicular cancer — more specifically, testicular germ cell tumors. Once again, however, the strength of the existing evidence was low.

        There was insufficient evidence that marijuana use was associated with an increased risk of other forms of cancer, including prostate, cervical, penile, and colorectal cancers.

        Dr. Ghasemiesfe and colleagues note that the studies that they had access to had many limitations, including numerous methodological problems and an insufficient number of participants who reported high levels of marijuana use.

        Going forward, the team suggests that there is an urgent need for better quality studies assessing the potential relationship between marijuana and cancer. The researchers conclude:

        “Misinformation [on this topic] may constitute an additional threat to public health; cannabis is being increasingly marketed as a potential cure for cancer in the absence of evidence, with enormous engagement in this misinformation on social media, particularly in states that have legalized recreational use.”

        “As marijuana smoking and other forms of marijuana use increase and evolve, it will be critical to develop a better understanding of the association of these different use behaviors with the development of cancers and other chronic conditions and to ensure accurate messaging to the public,” they add.

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          A recent study has identified an association between consuming two soft drinks per day and an increased risk of hip fracture in postmenopausal women. Because the study authors cannot prove causation, however, they call for more research.

          Osteoarthritis, which is characterized by progressively weak and brittle bones, predominantly affects older adults.

          As Western populations age, therefore, the incidence of osteoporosis rises in step.

          The condition affects around 200 million peopleTrusted Source worldwide. As a person’s bone mineral density becomes reduced, the risk of fractures increases.

          In fact, according to the authors of the most recent study paper, globally, an osteoporotic fracture occurs every 3 seconds.

          Although some of the primary risk factors for osteoporosis are unalterable, such as age and sex, some lifestyle habits also play a part.

          For instance, alcohol consumption and tobacco use both increase the risk. Nutrition may also play a role, with researchers particularly interested in calcium intake.

          One recent study in the journal Menopause focused on the impact of consuming soft drinks.

          Why soda?

          A number of older studies have observed a link between consuming soft drinks and reduced bone mineral density in teenage girlsTrusted Source and young womenTrusted Source.

          However, other studies that specifically looked for an association between soda and osteoporosis have not identifiedTrusted Source a significant relationship. One study found linksTrusted Source between cola intake and osteoporosis but did not see the same effect in relation to other sodas.

          Because of these discrepancies, the authors of the latest paper set out to study the links between soft drinks and bone mineral density in the spine and hip. They also looked for a relationship between soda intake and the risk of hip fracture over a 16 year follow-up period.

          To investigate, the scientists took data from the Women’s Health Initiative. This is an ongoing national study that involves 161,808 postmenopausal women. For the new analysis, the researchers used data from 72,342 of these participants.

          As part of the study, the participants provided detailed health information and questionnaire data outlining lifestyle factors, including diet. Importantly, the diet questionnaire included questions about their intakes of caffeinated and caffeine-free soft drinks.

          What did they find?

          During their analysis, the scientists accounted for a range of variables with the potential to impact the results, including age, ethnicity, education level, family income, body mass index (BMI), use of hormonal therapy and oral contraceptives, coffee intake, and history of falls.

          As expected, they did observe a relationship between soda consumption and osteoporosis-related injury. The authors write:

          “For total soda consumption, both minimally and fully adjusted survival models showed a 26% increased risk of hip fracture among women who drank on average 14 servings per week or more compared with no servings.”

          The researchers explain that the association was only statistically significant for caffeine-free sodas, which produced a 32% increase in risk. Although the pattern was similar for caffeinated sodas, it did not reach statistical significance.

          For clarity, the percentages above display relative risk, not absolute risk.

          The study authors reiterate that the significant link was only present when comparing the women who drank the most soda — at least two drinks per day — with those who drank none. This, they explain, suggests “a threshold effect rather than a dose-response relationship.”

          It is also worth noting that the scientists found no links between soda consumption and bone mineral density.

          Limitations and theories

          As mentioned above, earlier research looking for connections between soda and osteoporosis produced conflicting results. Although this study benefits from a large sample size, detailed information, and a long follow-up period, we cannot consider its results definitive; there is too much conflicting information.

          There are also certain limitations to the study. For instance, as the researchers note, the participants only reported soda consumption early in the study. People’s dietary habits can change significantly over time, and the team could not account for this.

          Also, although the researchers controlled for a wide range of factors, there is always the chance that an unmeasured factor played a part in this association.

          That said, when we look at studies involving other age groups, as well as studies using both men and women, it does seem that soda consumption overall might influence bone health in some way.

          The study authors believe that this might be because added sugars have a “negative impact on mineral homeostasis and calcium balance.”

          Another theory the authors outline concerns carbonation, which is the process of dissolving carbon dioxide in water. “It results in the formation of carbonic acid that might alter gastric acidity and, consequently, nutrient absorption.”

          However, they are quick to explain that “[w]hether this factor plays a role in these findings is yet to be explored.”

          Because osteoporosis is becoming more prevalent, research into nutritional risk factors is more critical than ever. The authors call for more work.

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            Pain under the left armpit can be concerning, and many people associate any pain on the left side of their body with a heart attack. However, most of the time, pain under the left armpit has a less serious cause.

            The armpit is a complex meeting point for muscles and connective tissues, lymph nodes, and blood vessels. As such, many issues in this area can lead to pain.

            Causes range from pulled muscles and mild allergic reactions to more severe issues, such as an underlying infection.

            While many of the causes of left armpit pain are not harmful in the long term, anyone experiencing breathing difficulties and pain in their chest, jaw, or neck should see a doctor immediately.

            Causes of left armpit pain include:

            A pulled muscle

            Many muscles around the shoulder and armpit can cause pain if a person injures them.

            People can pull a muscle when reaching for an object, twisting incorrectly, or overstretching.

            People who exercise regularly, especially those who do weight training, may be more likely to experience muscle pulls and strains.

            In these cases, the pain should go away over time, as long as the individual rests the injured muscle and does gentle stretches.

            If the pain does not go away after about a week, it is best to see a doctor.

            Allergic reactions

            Armpits are a frequent location for allergic reactions, which could cause pain under the left armpit or both armpits.

            Most allergic reactions in this area will occur due to chemicals people apply to their bodies or clothes that touch the armpits.

            Possible allergens include:

            • detergent
            • fabric softener
            • soap
            • deodorant
            • perfume
            • shaving cream
            • moisturizing creams or lotions

            These products may contain chemicals or perfumes that irritate the skin. A rash may also form.

            Anyone who suspects that their skin is sensitive to a particular allergen should note the products they used that day and report them to a dermatologist.

            Allergy testing may help find the irritating product. Avoiding products with any harsh chemicals or other ingredients can also improve symptoms in these cases.

            Cosmetic procedures

            Simple cosmetic procedures, such as shaving or waxing, can also be to blame for pain under the armpit. These hair removal techniques may lead to other issues, such as ingrown hairs, cysts, or general irritation and chafing in the armpit.

            Skin infections

            A skin infection under the armpit may cause itching and pain. Bacteria thrive in warm, damp environments such as the armpits.

            An overgrowth of bacteria in this area may lead to an infection, which could cause redness, swelling, and pain, among other symptoms.

            Other forms of infection, such as fungal infections due to ringworm or yeast, may also cause similar pain and irritation in the area.

            Mild skin infections should clear up without treatment if a person keeps the area clean and dry. However, a doctor may recommend antibiotic creams or medications to treat more severe cases.


            Hidradenitis is a chronic condition that causes similar symptoms to severe acne. Hidradenitis occurs due to clogged hair follicles and glands. It is common in areas such as the armpits, where the skin rubs together.

            Hidradenitis can lead to multiple cysts or boils developing in the area. In addition to these breakouts, the person will likely experience pain and tenderness.

            Doctors can treat hidradenitis with anti-inflammatory medications. Some cases may require surgery.

            Varicella zoster virus

            The varicella zoster virus causes chickenpox and shingles. Breakouts of both illnesses are possible under the armpits, although chickenpox usually beginsTrusted Source on the face, back, and chest.

            A shingles rash usually developsTrusted Source as a single strip on one side of the face or body, left or right. A person with shingles may also experience:

            • a fever
            • headaches
            • chills
            • an upset stomach

            A person may feel pain and tingling in the area before the visible rash develops.

            A doctor may prescribe antiviral medications to speed up the healing process, as well as pain medications to help ease symptoms.

            Swollen lymph nodes

            Lymph nodes are small, bean shaped bundles of tissue that play a vital role in the immune system. Lymph nodes help filter toxins from the lymph and deliver white blood cells to help fight disease.

            The armpit houses a large number of lymph nodes. Lymph nodes swell as part of an overall reaction by the immune system, such as to an infection or illness.

            Swollen lymph nodes in the armpit may cause:

            • a single or multiple lumps
            • tenderness
            • pain

            If the swelling does not go down after an infection, such as the common cold, goes away, or the person is not feeling any other symptoms, they should speak to a doctor.


            Psoriasis is an autoimmune condition that leads to an overgrowth of skin cells. The buildup of skin cells forms patches called plaques. These plaques can cause symptoms such as itching and pain.

            Psoriasis plaques can form anywhere, including the armpit. Some forms of psoriasis are more common in this area, including inverse psoriasis.

            Psoriasis treatment typically includes both topical and oral medications to control symptoms.

            Nerve damage

            Nerve damage may also cause pain under the armpit. Nerve damage can be the result of a physical injury, such as one from overuse during sports or from an accident or fall.

            Nerve damage can feel like:

            • pain
            • tingling
            • numbness
            • burning

            Certain conditions, such as diabetes, may also lead to nerve damage or neuropathy. The National Institute of Diabetes and Digestive and Kidney Diseases note that up to half of people with diabetes have peripheral neuropathy, which is nerve damage.

            While peripheral neuropathy typically affects the feet and legs, it may also affect the arms in some individuals. Diabetes treatment may help slow nerve damage progression.


            Angina occurs due to a lack of oxygen-rich blood flow to the heart. This can be because one of the arteries leading to the heart is narrow or blocked.

            Angina causes chest pain and discomfort, which is sometimes severe. It may also cause pressure and pain in other areas, including the:

            • armpits
            • shoulders
            • back
            • neck
            • jaw

            Some people may also experience a feeling similar to indigestion.

            Angina is a symptom of an underlying heart condition, for example, coronary heart disease, which can lead to a heart attack.

            There are also many other types of angina. Anyone who suspects they have angina should talk to their doctor.


            In rare cases, pain under the left armpit that does not go away may be a sign of a cancerous growth, including breast cancer.

            Cancer can cause the lymph nodes under the armpit to swell painfully. An individual may notice a lump under their arm or in their armpit that causes persistent pain or discomfort.

            Underarm pain may also be the result of a specific cancer treatment, such as lymph node removal or mastectomy.

            Anyone noticing texture changes or lumps in their chest or breast tissue should seek medical attention.

            Treatment options for cancer will depend on its stage, which refers to how much it has spread. In general, earlier stages are easier to treat.

            When to see a doctor

            Anyone noticing the following symptoms along with left armpit pain should seek immediate medical attention:

            • shortness of breath
            • dizziness
            • pain in the chest, jaw, or shoulder

            A doctor can also diagnose and treat pain from other issues, such as infections or swollen lymph nodes.

            Pain under the left armpit from sources such as a pulled muscle should go away within about a week in most cases. Anyone who experiences symptoms beyond this time frame should see a doctor for a full diagnosis.


            There are many possible causes of pain under the left armpit. The person may have pulled a muscle or may have swollen lymph nodes from an infection.

            Other causes can be more serious, such as angina. Anyone concerned about their symptoms should see a doctor for a full diagnosis and treatment.

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              A new study adds to the evidence that sleep deprivation has a significant effect on our day-to-day functioning. The authors warn that if we have slept poorly overnight, we are twice as likely to commit errors, some of which may well be very costly.

              Having a good night’s sleep is key to maintaining both physical and cognitive health. Our bodies know this instinctively, and researchers have proved many a time that this is true.

              For example, at Medical News Today, we have covered studies showing that sleep protects vascular health, helps maintain brain health, and may even give the immune response a boost.

              Conversely, poor sleep may lead to cardiovascular disease, contribute to depression, and increase a person’s risk of diabetes.

              Some researchers have also warned that sleep loss can affect aspects of our memory and visual perception so severely that driving after a sleepless night can be as dangerous as drunk driving.

              Following on from such evidence, researchers from Michigan State University’s Sleep and Learning Lab in East Lansing have conducted further research on sleep, attention, and higher order cognitive functioning.

              Their findings, which feature in the Journal of Experimental Psychology: General, show that sleep loss has an important effect not just on how well we can maintain our focus, but also on how well we can follow complex procedures — an aspect that they refer to as “placekeeping.”

              For their study, the investigators recruited 138 participants, whom they split into two groups: 77 people stayed in the laboratory overnight and had no sleep, while the remaining 61 participants slept at home.

              The evening before, all of the volunteers took part in two tasks. The first one measured their reaction time to a particular stimulus, and the second one assessed their place keeping abilities — that is, how well they were able to follow the particular steps of a complex process even with repeated interruptions.

              On the morning after, each participant had to repeat these tasks to see how their performance compared with that of the previous evening. The researchers found that the participants who had experienced sleep deprivation struggled significantly.

              “Our research showed that sleep deprivation doubles the odds of making place keeping errors and triples the number of lapses in attention, which is startling,” says study co-author Kimberly Fenn.

              “Sleep-deprived individuals need to exercise caution in absolutely everything that they do and simply can’t trust that they won’t make costly errors. Oftentimes — like when behind the wheel of a car — these errors can have tragic consequences,” she warns.

              Although it may not come as a surprise that lack of sleep reduces a person’s ability to focus, the researchers note that their recent study shows that sleep deprivation actually affects higher cognitive functioning, interfering with memory recall to a large extent.

              “Our findings debunk a common theory that suggests that attention is the only cognitive function affected by sleep deprivation,” says first author Michelle Stepan.

              “Some sleep deprived people might be able to hold it together under routine tasks, like a doctor taking a patient’s vitals. But our results suggest that completing an activity that requires following multiple steps, such as a doctor completing a medical procedure, is much riskier under conditions of sleep deprivation.”

              Michelle Stepan

              “After being interrupted [as they were performing complex tasks], there was a 15% error rate in the evening, and we saw that the error rate spiked to about 30% for the sleep deprived group the following morning,” notes the first author.

              “The rested participants’ morning scores were similar to the night before,” she adds. This finding, the investigators argue, should serve as a warning to people who experience sleep loss not to underestimate the effect that it can have on their daily lives.

              “There are some tasks people can do on autopilot that may not be affected by a lack of sleep. However, sleep deprivation causes widespread deficits across all facets of life,” Fenn emphasizes.