sleep accounts for one-quarter to one-third of the human lifespan. But what exactly happens when you sleep?
Before the 1950s, most people believed sleep was a passive activity during which the body and brain were dormant. “But it turns out that sleep is a period during which the brain is engaged in a number of activities necessary to life—which are closely linked to quality of life,” says Johns Hopkins sleep expert and neurologist Mark Wu, M.D., Ph.D. Researchers like Wu are spending many of their waking hours trying to learn more about these processes and how they affect mental and physical health. Here is a glimpse into the powerful (often surprising) findings of sleep researchers—and what they’re still trying to discover about the science of sleep.
All Sleep Is Not the Same
Throughout your time asleep, your brain will cycle repeatedly through two different types of sleep: REM (rapid-eye movement) sleep and non-REM sleep.
The first part of the cycle is non-REM sleep, which is composed of four stages. The first stage comes between being awake and falling asleep. The second is light sleep, when heart rate and breathing regulate and body temperature drops. The third and fourth stages are deep sleep. Though REM sleep was previously believed to be the most important sleep phase for learning and memory, newer data suggests that non-REM sleep is more important for these tasks, as well as being the more restful and restorative phase of sleep.
As you cycle into REM sleep, the eyes move rapidly behind closed lids, and brain waves are similar to those during wakefulness. Breath rate increases and the body becomes temporarily paralyzed as we dream.
The cycle then repeats itself, but with each cycle you spend less time in the deeper stages three and four of sleep and more time in REM sleep. On a typical night, you’ll cycle through four or five times.
recently identified a gene involved in the circadian regulation of sleep timing. When researchers removed this gene—called “wide awake”—from fruit flies, the flies experienced problems falling asleep and staying asleep. A similar sleep gene exish humans and mice. Scientists continue to study this gene in hopes of understanding more about how processes within our cells affect our ability to s
Your body essentially has its own alarm clock, called the circadian rhythm that is controlled by a biological clock located in the brain. One key function of this clock is responding to light cues, ramping up production of the hormone melatonin at night, then switching it off when it senses light. People with total blindness often have trouble sleeping because they are unable to detect and respond to these light cues.
Sleep drive also plays a key role: Your body craves sleep, much like it hungers for food. Throughout the day, your desire for sleep builds, and when it reaches a certain point, you need to sleep. A major difference between sleep and hunger: Your body can’t force you to eat when you’re hungry, but when you’re tired, it can put you to sleep, even if you’re in a meeting or behind the wheel of a car. When you’re exhausted, your body is even able to engage in microsleep episodes of one or two seconds while your eyes are open. Napping for more than 30 minutes later in the day can throw off your night’s sleep by decreasing your body’s sleep drive.
Why You Need Sleep
If you have ever felt foggy after a poor night’s sleep, it won’t surprise you that sleep significantly impacts brain function. First, a healthy amount of sleep is vital for “brain plasticity,” or the brain’s ability to adapt to input. If we sleep too little, we become unable to process what we’ve learned during the day and we have more trouble remembering it in the future. Researchers also believe that sleep may promote the removal of waste products from brain cells—something that seems to occur less efficiently when the brain is awake.
Sleep is vital to the rest of the body too. When people don’t get enough sleep, their health risks rise. Symptoms of depression, seizures, high blood pressure and migraines worsen. Immunity is compromised, increasing the likelihood of illness and infection. Sleep also plays a role in metabolism: Even one night of missed sleep can create a prediabetic state in an otherwise healthy person. “There are many important connections between health and sleep,” says Wu.
Getting good sleep is essential for overall health and well-being. If you're struggling with sleep, here are some tips to help you improve your sleep quality:
1. Maintain a Consistent Sleep Schedule:
Go to bed and wake up at the same time every day, even on weekends. This helps regulate your body's internal clock.
2. Create a Relaxing Bedtime Routine:
Develop a calming pre-sleep routine to signal to your body that it's time to wind down. This could include activities like reading, taking a warm bath, or practicing relaxation techniques.
3. Optimize Your Sleep Environment:
Make sure your bedroom is comfortable and conducive to sleep:
Keep the room dark, quiet, and at a comfortable temperature.
Invest in a comfortable mattress and pillows.
Remove or reduce sources of noise and light.
Consider using blackout curtains and white noise machines if needed.
4. Limit Exposure to Screens:
Avoid screens (phones, tablets, computers, TVs) at least an hour before bedtime, as the blue light emitted can interfere with your body's production of melatonin, a hormone that regulates sleep.
5. Be Mindful of What You Eat and Drink:
Avoid large meals, caffeine, and alcohol close to bedtime.
Limit liquids in the evening to reduce the likelihood of waking up for bathroom trips during the night.
6. Get Regular Exercise:
Engage in regular physical activity, but try to complete exercise at least a few hours before bedtime, as it can be stimulating.
7. Manage Stress:
Practice stress-reduction techniques like meditation, deep breathing, or progressive muscle relaxation to calm your mind before sleep.
8. Limit Naps:
If you need to nap during the day, keep it short (20-30 minutes) and avoid napping too close to bedtime.
9. Avoid Clock-Watching:
If you wake up during the night, try not to look at the clock. Clock-watching can create anxiety about not being able to fall back asleep.
10. Consider Cognitive Behavioral Therapy (CBT): - If you have persistent sleep problems, consider seeking help from a healthcare professional or therapist who specializes in CBT for insomnia. CBT can address underlying sleep-related issues and help you develop healthy sleep habits.
11. Evaluate Medications and Supplements: - Consult with a healthcare professional if you suspect that medications or supplements you're taking may be affecting your sleep. They can help adjust your treatment plan if necessary.
12. Get Sunlight Exposure During the Day: - Exposure to natural light during the day helps regulate your circadian rhythms and can improve sleep quality.
13. Be Patient: - Improving sleep habits often takes time. If you've tried various strategies and continue to have difficulty sleeping, consider consulting a healthcare professional for a thorough evaluation.
Remember that getting good sleep is crucial for physical and mental health, so prioritize it as an essential part of your daily routine.