The Importance of Sleep

Sleep, once considered a purely passive state, is now recognized as a complex process that supports the functions of every organ and system in your body. It is also a critical part of your mental health. During sleep, your brain processes the events of your day and replenishes your energy. You need good quality sleep to be able to think, react and learn. Inadequate or disrupted sleep may be associated with a variety of physical and emotional problems, including stress, weight gain, high blood pressure, memory loss and depression.

Researchers are still trying to understand why we need to sleep. One theory is that nighttime sleep developed as a way for early humans to avoid predators after dark and conserve energy. The need for sleep can be triggered by a number of conditions and activities, including illness, inactivity or travel, and it can increase with stress. In fact, stress is a major cause of poor sleep because it triggers the production of a chemical called cortisol that keeps you awake.

Scientists have discovered that our bodies need to go through the process of sleep-wake homeostasis, which is the regulation of your internal clock and the sleep drive. This system depends on signals from the suprachiasmatic nucleus, which is in a small region of the brain located near your optic chiasm. This is the part of the brain that controls your body’s circadian rhythm.

Your brain goes through different cycles during sleep, starting with light non-REM (non-dreaming) sleep and moving into REM sleep. During REM sleep, the eyes move rapidly behind closed lids, and the brain’s electrical activity increases to mimic the activity of your brain when you are awake. You may spend up to five cycles of this type of sleep during a night.

Research shows that sleep is important for a number of psychological and physical functions, such as preparing the brain to learn, remember and create. It is also important for sustaining your immune system and healing after illness or injury. Adequate amounts of sleep have been consistently tied to a healthier body (both inside and out), a better ability to concentrate, work, think and interact with others, and a lower risk for several chronic (long-term) health problems, including heart disease and diabetes.

Insufficient or interrupted sleep may be a sign of a serious medical condition, so it is important to see your doctor if you are not getting enough rest. A qualified health care professional can discuss strategies for improving your sleep habits, such as maintaining a regular bedtime and wake time and relaxing before going to sleep. A health care provider can also refer you to a specialist for further evaluation if necessary.