Wake up, folks: There is no health risk in rousing a sleepwalker from their somnambulistic stroll. Well, no risk to them, anyway. You, on the other hand, might suffer a swift, roundhouse kick to the dome.

Long-repeated medical myths have held that if you forcibly snap a sleepwalker back to a wakeful state it will A) induce a state of shock or possibly even insanity, B) give them “lockjaw,” and, C), our personal favorite, cause their soul to become trapped outside their body. The truth matters now more than ever: On Monday, the Stanford University School of Medicine released new research estimating that 8.5 million U.S. adults (3.6 percent of the grownup population) went sleepwalking during the past year -- a far higher rate of nocturnal wanderers than previously thought by doctors. 

“It’s not dangerous for the sleepwalker to wake him up,” said Dr. Mark R. Pressman, a psychologist and sleep specialist at Lankenau Hospital in Wynnewood, Pa. “You’re not going to do them any harm.”

But there are two potential pitfalls in attempting to yank them back to the conscious world. First, sleepwalkers take their short journeys with eyes open yet without turning on a key part of their brain -- the frontal lobe, a portion that controls social interaction. They are momentarily trapped in an altered, gray state that falls between alertness and full sleep, making them quite difficult to bring back to the real world, Pressman said.

“You just can’t talk to them and say ‘Hey!” and have them wake up,” Pressman said. “I’m not even sure where that myth began that you shouldn’t wake them. But the more you dig back (to try research that legend), the more you’ll find that sleepwalking once was thought to be mixed in with spirits and demonic possessions.”

Most sleepwalking episodes last only seconds or a few minutes, ending with the person either sitting or lying on the floor and returning sleep or eventually trudging back to bed.

“It’s very likely to go away on its own while the family is watching,” Pressman said.

You can try to verbally redirect a sleepwalker -- especially a child -- by standing a short distance away and speaking to them in short, easy commands: “Stop, turn around, go back to bed.” But don’t expect them to answer or even to recognize you, Pressman said. Those particular neurons are still snoozing. “Hopefully they turn around and go the other way.

“There’s really no reason to dive in and stop it unless the sleepwalker is about to climb out a window or fall down some stairs. If that’s the case, the family member doesn’t really have much choice,” he added.

If you do approach a sleepwalker -- especially if you physically block or grab one -- they may flash some "defensive aggressiveness,” Pressman said. “This is a very primitive response to what they see as a potential attacker. They may become violent.

“The first thing, obviously, is you have to protect them anyway you can. That’s the bottom line: safety. So you may have to be prepared to take a punch or kick.”

Just don’t expect your zombified loved one or housemate to offer an apology. 

Related:

• Sleepwalking more rampant than thought, study shows
• Suicide while sleepwalking is a real nightmare
• Why do our eyelids get heavy when we're sleepy?

By Abby Lerner
Men's Health

Getty Images stock

If you feel sick -- and you never get sick -- your immune system may be suffering from too little sleep.

Need a reason to hit the snooze button a few more times? Sleep is as vital for survival as food, according to Dr. Mary Susan Esther, president of the American Academy of Sleep Medicine (AASM). And chances are you're more likely to burn the midnight oil to finish all your work (and play) than you are to pass up dinner. But chronic lack of sleep can lead to a host of health problems, such as high blood pressure, obesity, depression, irregular hormone production, a weakened immune system, memory lapses, constant irritability, and decreased concentration and reaction times.

So are you spending enough quality time between the sheets, asleep? See how many of the signs below describe you. Then decide if a sleep deficit is holding you back.

How to Sleep Right, Tonight

1. You're not hungry for lunch. A lack of sleep can make you constantly want to eat more, or persistently feel like you're not hungry. It throws off your internal clock resulting in abnormal feelings, which is why so many people lose or gain weight during periods of sleeplessness.

2. You've looked at three other Web sites in the last 5 minutes, and checked your email twice. No, you (probably) don't have Attention Deficit Disorder. Whether you're writing a quick email or solving chemical equations; a lack of sleep can make focusing seem impossible.

3. You can't remember where you put the car keys. Your brain needs sleep to refresh and regenerate. Without it, your short-term memory may be impaired, which is why pulling an all-nighter rarely yields better results than getting quality shut-eye, according to Dr. Neil Kline, a sleep physician and representative of the American Sleep Association.

Is Sleep Really Necessary?

4. You can't carry on a conversation. Come Saturday night you may work a party like a pro, but as long as you're sleep-deficient, coming up with witty, or even coherent, one-liners is out of the question.

5. You're drowsy at the wheel. Your eyes may glaze over now and then when you're staring at the computer screen or stuck in an endless meeting, but if you struggle to stay awake behind the wheel, or doing any task that puts your life at risk, you're not just bored. You need more sleep.

Caffeinated drinks, blasting music, or rolling down the windows (in January) may arouse you briefly, but it won't keep you alert for long drives.

6. You feel sick, and you never get sick. Your immune system repairs and strengthens while you sleep. So in addition to eating flu-fighting foods, log at least seven hours a night to stay healthy all season.

Boost Your Immune System Now

More Links:

Sleep Better Tonight

The Cost of Lost Shut-Eye

14 Barriers to Deep Sleep

The Cities That Never Sleep

Got a bad case of the Mondays? If you struggled to get out of bed this morning, or are struggling not to do a face-plant at your keyboard right now, Dr. Roshini Raj has some advice. A TODAY contributor and contributing medical editor at Health magazine, Dr. Raj offers these tips (and more in the video) for finding more energy:

Turn off the light: Avoid "blue light" from your tech devices after dinner; blue light has the biggest impact on circadian rhythm, slowing production of melatonin, a hormone that helps us sleep.

Power snack: Don't skip meals, and eat every four hours; the perfect snacks are fewer than 200 calories and include a mix of carbs, protein and fiber. Examples: One hardboiled egg and one banana; a cup of Greek yogurt with fresh or frozen blueberries; one pear and three slices of turkey breast.

Related: Guzzling energy drinks but more tired than ever

Get out: It's not your imagination, going outside does energize you. Music has a similar effect, especially if you move to the beat -- even if it's just tapping your feet.

B12 shots? Probably not: Though they've become something of a fad recently, Dr. Raj says that unless you are actually deficient in vitamin B12, a shot of it won't affect your energy level.

Finally, if you're deeply fatigued all of the time and the normal advice for restoring energy seems to work, see a doctor. There could be an underlying medical problem at the root.

Related stories:

9 fast fixes for more energy 

The dangers of sleeping pills

Getty Images file Getty Images file

By Andrew Winner

Wondering if it’s time for another cup of coffee? Just take a look at your iPhone. A new software application from The Pennsylvania State University shows users the optimal time to consume caffeine and when to reach for the decaf.

Dr. Frank Ritter, who created the app along with Dr. Martin Yeh, isn’t trying beat the drum against the country’s coffee habit. Rather, he believes the application’s graphical output presents a novel way for individuals to conceptualize their caffeine consumption.

While it may not kill anyone, caffeine can be a nasty mistress if usage isn’t monitored correctly.

Nervousness and disrupted sleep patterns are just two of the negative consequences of caffeine, with users sometimes becoming so inured to the negative effects of caffeine they aren’t consciously aware of the worsening effects. Additionally, caffeine can have a cumulative effect—too much on Monday could lead to disrupted sleep and grogginess on Tuesday. People attempt to self-correct by increasing their intake on Tuesday, creating a cycle that dramatically affects sleep habits and quality of life.

Caffeine Zone helps individuals understand how long caffeine stays in the system, helping them to avoid such Catch-22s and achieve better sleep.

“Increased levels of caffeine can inhibit normal sleep—at least it does for me,” Ritter said in an e-mail. “A colleague of mine used to talk about using caffeine to fight sleep deprivation, and I think that many of us do that.”

“I have also used the app to avoid caffeine way before a talk so I could have a coffee to hand while giving a talk, and then be able to sleep normally,” Ritter added. “If I had not, I would have had a lot of coffee in anticipation of giving a talk in the afternoon, and would not have gotten rid of the caffeine before bedtime.”

The mobile application prompts users to input their caffeine consumption. Then, using preexisting models of caffeine half-lives, the estimated amount of caffeine in the body is shown on a graph. This allows users to review their caffeine level at a glance – information that could be very useful for those dealing with shift changes at work, for example, or our friends in the Armed Services.

Ritter, of Penn State’s Applied Cognitive Science Lab, was encouraged to study the effects of caffeine by Dr. Susan Chipman with the Office of Navy Research. As one might imagine, the working environment on a submarine lends itself to massive amounts of caffeine intake. Understanding one’s level of caffeine could increase mental acuity and improve quality of life of submariners at sea.

Additionally, the basic platform Ritter created can be extended to monitor different substances. Ritter is also hoping to make caffeine half-life a changeable parameter in the app to account for those who “caffeine” differently.

“This started as an experiment in understanding caffeine and how to deliver and work with mobile apps, but it has grown more than we thought it would,” Ritter said. “We have gotten numerous suggestions from this process and a lot of encouragement.”

With an estimated 80-90 percent of the North American population consuming some amount of caffeine daily and a per-capita usage rate of 280 milligrams for adults, it’s important for the general population to understand the effects of caffeine.

Ritter hopes the app will help educate the public on when a hit of caffeine can improve mental function—and when it can do more harm than good.

Related:

• Tank up on java, release your inner editor
• That coffee buzz is all in your head
• Sleepy people blame others for everything

Seven hours of sleep a night is enough for most older teens, research shows.

If your teen’s lack of sleep is keeping you up nights, a new study should help put your mind at ease.

National guidelines recommend at least eight hours of serious snooze time a night for young people. But that’s an unrealistic goal for adolescents, who are overloaded with homework, extracurricular activities and part-time jobs, experts say. Or who feel the need to stay up late texting friends or updating Facebook.

In fact, if standardized test performance is any indication, 16-year-olds score best with about seven hours of sleep a night, surprising new research finds.

Brigham Young University economists Eric Eide and Mark Showalter -- who are also dads -- used a nationally representative sample of 1,724 students, comparing children’s and teens’ standardized test scores with the amount of sleep they reported.

For older teens, seven hours a night was plenty. The optimal amount of sleep for 12-year-olds was higher, about eight hours, while 10-year-olds did best with about nine hours. The report appears in the current issue of the Eastern Economics Journal.

“If your kid’s not getting nine hours of sleep, maybe you don’t have to worry so much,” Showalter says, unless they’re regularly getting significantly less. “Certainly there is good scientific evidence that extreme sleep deprivation or oversleeping has serious health consequences,” he says.

Showalter believes the current recommendations are based on surveys of adolescents in the 1970s. The teens were brought into a lab a few days a year for three years and told to sleep as long as they wanted to. Any parent of a teen knows that how much they want to sleep could be way more than how much they need to sleep.

“We couldn’t find much scientific empirical backing for the common recommendations,” Showalter says, echoing a paper that came out last week in the journal Pediatrics. That report, by Australian researchers, concluded that “no matter how much sleep children are getting, it has always been assumed that they need more.”

What about research suggesting students are more alert in morning classes with later start times?

That might have more to do with how early the teen has to get out bed, Showalter says, rather than the total time spent in bed.

How much sleep a night do your kids get? Tell us on Facebook.

Related stories:

Kids don't get enough sleep (and neither did their grandparents)

Sleepy teen engage in more risky behavior

'Sleep debt' tied to attention trouble in teens

By Cari Nierenberg
MyHealthNewsDaily Contributor

Parents the world over have been worrying about whether their children get enough sleep for more than a century, a new study shows. 

The study also found that, even as recommendations about how much sleep kids need have changed since the late 1800s, studies have shown that kids get less sleep than recommended.

"We were surprised that over the last century, the actual amount of sleep that children are getting was consistently about 37 minutes less than what was recommended for them," said lead study author Lisa Anne Matricciani, of the University of South Australia in Adelaide.

And for the last 100 years, "modern living" has been blamed for robbing kids of shuteye, according to the research. The bedtime-delaying culprits have changed with the technologies of the time, from the electric light bulb and the radio in the earlier parts of the 20th century, to the social media and video games of today.

The study is published today (Feb.13) in the journal Pediatrics.

Recommendations vs. actual sleep
To explore the historical trends in sleep recommendations, and compare them to data on the actual amount of time children and teens were sleeping, Australian researchers collected information and studies dating from 1897 to 2009.

They found 32 sets of age-specific sleep recommendations for children, and more than 200 articles that reported on how much actual sleep children got.

The advice by experts of how much sleep children and teens need tend to exceed what kids really get by roughly 30 minutes, whether the year was 1908 or 2008. Although age-specific sleep recommendations declined over the century, the actual amount of sleep that children got declined at a nearly identical rate.

Insufficient sleep in children has been linked with poor academic performance, an increased risk for obesity, higher rates of drug and alcohol use and more frequent injuries.

"The rationale for sleep recommendations was also strikingly consistent for more than 100 years -- that children were overtaxed by the stimulation of modern living," Matricciani said.

But what she and the research team found most remarkable was that there was almost no solid, empirical evidence to support the sleep recommendations being made for children.

"This is not to say that kids don't, in fact, need more sleep, just that the evidence is not out there," said Timothy Olds, a professor of health sciences at the University of South Australia, who also worked on the study. Sleep recommendations may reflect ingrained biases -- that kids are sleep-deprived or the world is going too fast -- more than good science, he said.

Perhaps parents "should take sleep recommendations for children with a grain of salt," Olds suggested.

Watch your child
The best way for parents to determine if a child is getting enough sleep is to "watch your child, and not the clock," said Dr. Marc Weissbluth, an expert on childhood sleep problems and a professor of pediatrics at Northwestern University Feinberg School of Medicine in Chicago.

In his book, "Healthy Sleep Habits, Happy Child" (Ballantine Books, 1999), Weissbluth does not offer sleep recommendations, but instead tells parents to observe certain signs and symptoms.

Look at a child's mood, personality and performance near the end of the day, he advised. If your child is under age 3 and napping, look at them between 4 p.m. and 5 p.m.; for a child age 3 or older, look between 5 p.m. and 6 p.m.

Is your child sweet, adaptable and well-functioning, or short-fused, clingy and irritable? This can tell parents whether a child is well-rested or overtired, and whether naps or bedtimes need to be adjusted, Weissbluth said. 

Weissbluth said that even though there might be an absence of evidence about exactly how much sleep children need this shouldn't leave parents with the impression that kids are getting enough shuteye.

Rather than focusing solely on the number of hours a child sleeps each night, he advises parents to focus on how a child appears near the end of the day, and when sleep is occurring. 

• 10 Ways to Promote Kids' Healthy Eating Habits
• 10 Medical Myths that Just Won't Go Away
• Top 10 Spooky Sleep Disorders

By Julie Evans
Prevention

We all tend to blame fatigue on a too-busy lifestyle. And much of the time we’re right.

If you feel tired all the time, don’t blow it off. Give yourself about 2 to 3 weeks to make some lifestyle changes. Get more sleep, trim your social calendar, eat more wholesome foods, drink more fluids, take a multivitamin, and cut back on caffeine and alcohol.

"If you're still feeling the symptoms of fatigue after those changes, then you need professional help," says Sandra Adamson Fryhofer, MD, an internal medicine doctor in Atlanta. Excess exhaustion could be the sign of a more serious medical condition that can  be treated. Here are the 7 most common problems to know about.

Try This First: Tricks to Sleeping Better Every Night

1. Anemia

This condition is more common in women with heavy periods or who don’t consume enough iron. 

The fatigue caused by anemia is the result of a lack of red blood cells, which bring oxygen from your lungs to your tissues and cells. You may feel weak and short of breath. Anemia may be caused by an iron or vitamin deficiency, blood loss, internal bleeding, or a chronic disease such as rheumatoid arthritis, cancer, or kidney failure. Women of childbearing age are especially susceptible to iron-deficiency anemia because of blood loss during menstruation and the body's need for extra iron during pregnancy and breastfeeding, explains Laurence Corash, MD, adjunct professor of laboratory medicine at the University of California, San Francisco.

The symptoms: Fatigue is a major one. Others include extreme weakness, difficulty sleeping, lack of concentration, rapid heartbeat, chest pains, and headache. Simple exercise, such as climbing the stairs or walking short distances, can cause fatigue.

The tests: A thorough evaluation for anemia includes a complete physical exam and blood tests, including a complete blood count (CBC), to check the levels of your red blood cells. It's also standard to check the stool for blood loss.

Quick Energy-Boosting Tricks 

2. Diabetes

More than a million people are diagnosed with type 2 diabetes every year, but many more may not even know they have it.

Sugar, also called glucose, is the fuel that keeps your body going. And that means trouble for people with type 2 diabetes who can't use glucose properly, causing it to build up in the blood. Without enough energy to keep the body running smoothly, people with diabetes often notice fatigue as one of the first warning signs, says Christopher D. Saudek, MD, professor of medicine and program director for the General Clinical Research Center at the Johns Hopkins University School of Medicine.

The symptoms: Aside from exhaustion, other signs include excessive thirst, frequent urination, hunger, weight loss, irritability, vaginal yeast infections, and blurred vision.

The tests: There are two major tests for diabetes. The fasting plasma glucose test, which is more common, measures your blood glucose level after fasting for 8 hours, usually first thing in the morning. With the oral glucose tolerance test (OGTT), blood is drawn twice: just before drinking a glucose syrup, then 2 hours later.

Power Breakfasts That Lower Your Blood Sugar

3. Thyroid Disease

When your thyroid hormones are out of whack, even everyday activities will make you feel wiped out.

The thyroid gland, about the size of the knot on a man's tie, is found in the front of the neck and produces hormones that control your metabolism. Too much thyroid hormone (hyperthyroidism), and metabolism speeds up. Too little (hypothyroidism), and metabolism slows down.

The symptoms: Hyperthyroidism causes muscle fatigue and weakness, which you may notice first in the thighs. Exercises such as riding a bike or climbing stairs become more difficult. Other symptoms include unexplained weight loss, feeling warm all the time, increased heart rate, shorter and less frequent menstrual flows, and increased thirst. Hyperthyroidism is most commonly diagnosed in women in their 20s and 30s, but it can occur in older women and men too, says Robert J. McConnell, MD, codirector of the New York Thyroid Center at Columbia University Medical Center in New York City.

Hypothyroidism causes fatigue, an inability to concentrate, and muscle soreness, even with minor activity. Other symptoms include weight gain due to water retention, feeling cold all the time (even in warmer weather), heavier and more frequent menstrual flows, and constipation. Hypothyroidism is most common in women over age 50. In fact, as many as 10% of women past 50 will have at least mild hypothyroidism, says McConnell.

The tests: Thyroid disease can be detected with a blood test. "Thyroid disorders are so treatable that a thyroid test should be done in all people who complain of fatigue and/or muscle weakness," says McConnell.

4. Depression

More than "the blues," depression is a major illness that affects the way we sleep, eat, and feel about ourselves and others.

Without treatment, the symptoms of depression may last for weeks, months, or even years. So it's important to recognize the warning signs and get help.

The symptoms: We don't all experience depression in the same way. But commonly, depression can cause decreased energy, changes in sleeping and eating patterns, problems with memory and concentration, and feelings of hopelessness, worthlessness, and negativity.

Surprising Ways Depression Boosts Your Health 

The tests: There’s no blood test for depression, but your doctor may be able to identify it by asking you a series of questions. If you experience five or more symptoms below for more than 2 weeks, or if they interfere with your life, see your doctor or mental health professional. Your doctor may also recommend a thorough physical exam to rule out other issues.

• Fatigue or loss of energy
• Sleeping too little or too much
• A persistent sad, anxious, or "empty" mood
• Reduced appetite and weight loss, or increased appetite and weight gain
• Loss of interest or pleasure in activities once enjoyed
• Restlessness or irritability
• Persistent physical symptoms that don't respond to treatment, such as headaches, chronic pain, or constipation and other digestive disorders
• Difficulty concentrating, remembering, or making decisions
• Feeling guilty, hopeless, or worthless
• Thoughts of death or suicide

5. Rheumatoid Arthritis

This autoimmune disease is not always easy to diagnose early, but there are some subtle clues to look for.

RA happens when your immune system turns against itself and attacks healthy joint tissue, sometimes resulting in irreversible damage to bone and cartilage.

The symptoms: Many symptoms (such as fatigue, low energy, loss of appetite, and joint pain) are shared by other health conditions, including other forms of arthritis such as fibromyalgia and lupus. Also, anemia and thyroid disorders, which also cause fatigue, are even more common in people with RA, according to John Klippel, MD, president and CEO of the Atlanta-based Arthritis Foundation.

Rheumatologists look for at least four of the following criteria in diagnosing RA: morning stiffness in and around the joints lasting at least 1 hour before maximum improvement; at least three joint areas with simultaneous soft tissue swelling or fluid; at least one joint area swollen in a wrist, knuckle, or the middle joint of a finger; simultaneous involvement of the same joint areas on both sides of the body; lumps of tissue under the skin; and bone erosion in the wrist or hand joints, detected by x-ray.

The tests: A thorough physical exam by a rheumatologist can provide some of the most valuable evidence of the disease, but there is also a test for the presence of rheumatoid factor, an antibody found in the blood. About 80% of people with RA test positive for this antibody, but the test is not conclusive.

Important Questions About Arthritis, Answered 

6. Sleep Apnea

You could have this sleep-disrupting problem if you wake up feeling tired no matter how much rest you think you got.

Sleep apnea is a disorder characterized by brief interruptions of breathing during sleep. In the most common type, obstructive sleep apnea, your upper airway actually closes or collapses for a few seconds, which, in turn, alerts your brain to wake you up to begin breathing again. Someone with obstructive sleep apnea may stop breathing dozens or even hundreds of times a night, says Roseanne S. Barker, MD, former medical director of the Baptist Sleep Institute in Knoxville, TN.

The symptoms: Sleep apnea is often signaled by snoring and is generally followed by tiredness the next day. Because sleep apnea can lead to heart disease, high blood pressure, and stroke, it's important to be tested.

The tests: This involves an overnight stay at a sleep clinic, where you'll undergo a polysomnogram, which is a painless test that will monitor your sleep patterns, breathing changes, and brain activity.

Are you sleepy today? How many hours of sleep did you get last night? Talk about this story on Facebook. 

More from Prevention: 

• Top 10 Reasons You Aren’t Getting Enough Sleep
• The Best Time To Schedule Your Health Tests 
• 10 Things You Should Know About Fibromyalgia
• How to Ace Your Next Health Screening