Every night, your body performs one of its most essential functions: sleep. Although it may seem like nothing is happening when you close your eyes, your brain is actually working harder during some stages of sleep than when you are awake.

Sleep occurs in cycles that last about 90 minutes each. During a full night's rest, you typically go through four to six of these cycles. Each cycle contains four stages. The first three stages are called non-REM sleep, and the fourth is called REM (Rapid Eye Movement) sleep.

During the deep stages of non-REM sleep, your body repairs muscle tissue, strengthens the immune system, and releases growth hormones. This is why sleep is especially important for teenagers, whose bodies are still growing and developing.

REM sleep is when most dreaming occurs. During this stage, your brain processes emotions, consolidates memories, and sorts through the information you absorbed during the day. Research shows that students who get adequate sleep perform significantly better on tests than those who stay up late studying. The brain literally needs sleep to move information from short-term to long-term memory.

Despite its importance, many teenagers do not get enough sleep. The American Academy of Sleep Medicine recommends that teenagers get eight to ten hours of sleep per night. However, studies show that nearly 73 percent of high school students get fewer than eight hours on school nights.

Several factors work against teen sleep. Biological changes during puberty shift the body's internal clock, making it difficult to fall asleep before 11 p.m. Early school start times, homework, extracurricular activities, and screen time all reduce the hours available for rest.

The consequences of sleep deprivation are serious. Insufficient sleep is linked to difficulty concentrating, mood swings, weakened immunity, weight gain, and increased risk of accidents. Over time, chronic sleep loss can affect mental health and academic performance.

Improving sleep habits is possible. Experts recommend keeping a consistent sleep schedule, avoiding screens for at least 30 minutes before bed, keeping the bedroom cool and dark, and avoiding caffeine in the afternoon and evening. Even small changes can lead to meaningful improvements in sleep quality.