Nobody knows why people need sleep. Most of the time, no matter how much we’re fighting it, the body will eventually shut down to get some rest.

Many people, however, seem to believe they know why we can’t fall asleep easily and what we can do to fix that inconvenience.

Why someone is sleep deprived is usually his or her own fault. Daily habits and life style get in the way. But don’t be quick to judge because they may have been misinformed, causing a vicious cycle of bad habits leading to chronic tiredness.

The quality of sleep during the day is not the same, Dr. Karl Doghramji, Director of the Sleep Disorders Center at Thomas Jefferson University Hospital, says. “One hour of sleep at night does not equal an hour of sleep in day time due to your biological clock trying to keep you awake,” he adds. You make wake up often and not reach REM sleep. 

Quick power naps, which may be a secret to live a long, happy life, can make you more alert. Napping during the day is especially beneficial to people who work in shift, according to Dr. Doghramji. The best kind of nap is 20-30 minutes long and taken around the same time during the day, he adds. Avoid extended naps after 4 p.m. because they can mess with your ability to fall asleep later.

Getting up at 6 a.m. every day, and then suddenly sleeping until 1 p.m. on weekends, disrupts the body’s internal clock. “Don’t extend your wakeup time during the weekend by more than an hour or you’ll pay the price,” Dr. Doghramji says. On Monday and Tuesday your body will want to sleep more and you’ll feel tired and groggy all day.

“This is a contradictory question to which science doesn’t have a great answer,” Dr. Doghramji says. Some experiments show that older people are not sleepier during the day if they haven’t slept much at night, but others indicate the opposite. They need as much sleep as when they were in their 30s, but the quality had decreased because health problems mess with our ability to sleep. This is where the misconception probably comes from, he adds.

How much sleep people need varies with every person and is also genetically determined, Dr. Doghramji says. Some people, depending on age, lifestyle and habits (some of which may cause premature aging), may need five hours while others can’t function unless they get at least 12 hours of shuteye. “The best way to judge is if you feel great after several weeks of sleeping certain amount of hours, “he adds.

About half of the population snores, according to Dr. Neil Kline, a sleep physician and representative of American Sleep Association. You’re snoring because the brain is signaling it’s not getting enough oxygen. “There is new research that is suggesting that simple snoring may be associated with negative health outcomes,” he says.  There are treatments for snoring, which can be a sign of obesity, including surgery, weight loss if overweight, and snoring mouthpieces.  “For about 5-10 percent of the adults, snoring is a symptom of a potentially dangerous sleep disorder, sleep apnea,” he says.

Insomnia is a very common problem that most adults will experience at some point. “Taking sleeping medications is common practice,” Dr. Kline says. “However, there is alarming evidence that taking sleeping pills can increase risk for other health dangers.” Some pills last longer in the body causing daytime sleepiness which comes with its own risks of falling, hurting yourself and getting in a car accident. Some people take them for longer than they should and the risk of overdosing becomes serious, Dr. Doghramji says.

“I just saw a 3-year-old kid this morning whose mother brought him in because he stops breathing 20 times an hour at night,” Dr. Doghramji says. In fact, the number of children with sleep apnea has increased because of a rise in obesity among kids. Children with untreated sleep apnea run the risk of having behavioral, adaptive, and learning problems, according to Alaska Sleep Clinic.

Even though people are walking, they are still in deep, deep sleep, Dr. Doghramji says. Waking up a somnambulist is not physically dangerous but it can make him or her very nervous and frightened because their mind is still kind of sleep, he adds. They won’t know what’s happening for a few minutes. That’s why it’s recommended to just gently direct the sleepwalker back to bed.

Lack of sleep can cause your brain to shrink, increase your blood pressure, and make you very tired. But that’s not all. Your growth hormones are affected because your brain is not functioning to the best of its ability. Sleep deprivation also leads to weight gain, makes you susceptible to diseases, and hurts your skin by releasing cortisol, the stress hormone, which breaks down collagen.

Alcohol is eliminated from the body rapidly and causes withdrawal symptoms two or three hours later, Dr. Doghramji says, which have a negative reaction. “You wake up very often but very briefly, and you don't even remember,” he adds. But still, the quality if your sleep is low. Studies have shown that in healthy people, acute high alcohol doses disturb sleep, whereas in insomniacs, lower doses may be beneficial.

Too much screen time in bed is one of the worst things you can do to yourself. Televisions emit blue light, which affects the levels of the sleep-inducing melatonin more than any other wavelength, Dr. Doghramji says. Another problem is what you’re watching. Chances are a movie or a late show that you find will be more stimulating than relaxing, keeping you awake.

It’s about conditioning. If you stay in bed when you’re not sleeping, then your body will learn to stay wake when you’re in bed and it’ll be harder and harder to fall asleep. Don’t use your bed as an office for answering phone calls and responding to emails, according to Harvard Medical School. The bed has to play the role of a sleeping stimulant, not restlessness. “Get out of bed for 20-30 minutes, do some yoga, mediate or read a boring book,” Dr. Doghramji says. Then go back to bed and try again.

“The time you wake up determines the ability to fall asleep at night,” Dr. Doghramji says. If you wake up late, falling asleep may be a problem.  The bigger the difference in shut-eye time, the more jetlag symptoms you’ll experience.