Research has uncovered many of the nuts and bolts that link the need for sleep to the chemistry of life in the brain and virtually every part of our body. Insufficient sleep damages areas of the brain involved in managing stress, learning, and memory. Individuals who experience excessive sleepiness are often unable to perform at school or in the workplace. Sleep problems also contribute to the risk of serious medical conditions and the management of mental health illnesses.
The brain lives in a fluid that is important for its continued health across the lifespan. Researchers have discovered that during sleep the flow of this fluid is redirected deeper into the cortex, the thinking part of the brain, where it helps flush out waste products that contribute to the risk of Alzheimer's and other neurological disorders.
New evidence indicates that sleep is also important to maternal and fetal health during pregnancy. Untreated sleep disorders during pregnancy may threaten the health of approximately 500,000 pregnant women and their unborn babies each year.
Studies are now under way to determine how poor sleep and difficulty breathing during sleep contribute to the risk of gestational medical conditions such as diabetes, hypertension, and pre-term delivery. A landmark NIH-supported study called nuMoM2b found that pregnant women with difficulty breathing during sleep (sleep apnea) are more likely to develop hypertension and preeclampsia—a pregnancy complication that includes high blood pressure and organ damage, often to the kidneys. These women are also three times more likely to develop gestational diabetes compared with pregnant women who do not have difficulty breathing during sleep.
Mounting evidence indicates that irregular sleep and untreated sleep disorders may contribute to health disparities. A landmark study funded by the National Heart, Lung, and Blood Institute (NHLBI) on Hispanic community health—The Hispanic Community Health Study/Study of Latinos—has revealed that sleep apnea, which is characterized by difficulty breathing during sleep, is common and rarely diagnosed and treated. Approximately 26 percent of the more than 1400 study participants had sleep disordered breathing which is associated with increased risk for developing high blood pressure, heart disease, diabetes, and stroke. The study also found that sleep apnea was associated with peripheral arterial disease, a condition in which narrowed arteries reduce blood flow to the arms and legs.
What Are Sleep Studies?
Sleep studies are tests that measure how well you sleep and how your body responds to sleep problems. These tests can help your healthcare provider find out whether you have a sleep disorder and how severe it is. Sleep studies are important because untreated sleep disorders can raise your risk for heart disease, high blood pressure, stroke, and other medical conditions. Sleep disorders also have been linked to an increased risk of injury, such as falling, particularly among the elderly, and car accidents.
Research is helping to improve our understanding of the connection between sleep disorders and our physical, mental, and behavioral health. NIH supports a range of sleep-related research that focuses on:
- Better understanding of how a lack of sleep increases the risk for obesity, diabetes, heart disease, and stroke.
- Genetic, environmental, and social factors that lead to sleep disorders.
- The adverse effects from a lack of sleep on body and brain.