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Sleep: What really happens?

Sleep affects how we look, feel and perform on a daily basis and has a major impact on our overall quality of life.

To receive optimal sleep, both quality and quantity matter. If sleep is cut short, the body doesn’t have time to complete all phases needed for muscle repair, memory consolidation and release of hormones regulating growth and appetite. We wake up less prepared to concentrate, make decisions or engage fully at work, school and social activities.

Sleep architecture follows a pattern of alternating between NREM (non-rapid eye movement) and REM (rapid eye movement) sleep throughout a typical night in a cycle that repeats about every 90 minutes. As we begin to fall asleep, we enter NREM sleep, which is composed of stages 1-3 and typically comprises 75% of the night.

Stage 1 is a light sleep and occurs between being awake and falling asleep.

Stage 2 occurs after sleep onset. Breathing and heart rate are regular, body temperature drops and we become disengaged from our surroundings.

Stage 3 is the deepest and most restorative sleep. Blood pressure drops, breathing becomes slower, muscles relax and blood supply to muscles increase, allowing tissue growth and repair. Energy is restored, hormones are released, and short-term memory downloads into long-term memory.

REM sleep first occurs about 90 minutes after falling asleep and recurs about every 90 minutes, getting longer later in the night, and comprises approximately 25% of the night. During REM sleep, the brain is active and dreams occur, the eyes dart back and forth, and the body becomes immobile and relaxed, as the muscles are turned off. It provides energy to the brain and body, supports daytime performance and is important for mood stabilization.

The one-third of our lives that we spend sleeping plays a direct role in how full, energetic and successful the other two-thirds of our lives can be.

According to the National Institutes of Health, 50 million to 70 million Americans are affected by chronic sleep disorders and intermittent sleep problems that can significantly diminish health, alertness and safety. Untreated sleep disorders have been linked to hypertension, heart disease, stroke, depression, diabetes and other chronic diseases. Sleep problems can take many forms and can involve too little sleep, too much sleep or inadequate quality of sleep.

Most people know when to seek medical help for physical discomfort such as pain or a fever, however, sleep problems are often overlooked or ignored. The majority of people with sleep disorders are undiagnosed and untreated.

To determine whether a sleep evaluation is indicated, consider the following questions:

• Do you regularly have difficulty getting to sleep or staying asleep?

• Do you snore? Has anyone told you that you have pauses in breathing or gasp while sleeping?

• Are your legs active at night? Do you feel tingling, creeping, itching, pulling or aching in your legs?

• Are you so tired when you wake up in the morning that you cannot function normally during the day?

• Does sleepiness and fatigue persist for more than two to three weeks?

If the answer is “yes” to any of these questions, consider a complete sleep evaluation.