section_path: Sleep health
section_name: Sleep health
paragraph_text: Sleep health
  
  Low quality sleep has been linked with health conditions like cardiovascular disease, obesity, and mental illness. While poor sleep is common among those with cardiovascular disease, some research indicates that poor sleep can be a contributing cause. Short sleep duration of less than seven hours is correlated with coronary heart disease and increased risk of death from coronary heart disease. Sleep duration greater than nine hours is also correlated with coronary heart disease, as well as stroke and cardiovascular events.
  
  In both children and adults, short sleep duration is associated with an increased risk of obesity, with various studies reporting an increased risk of 45–55%. Other aspects of sleep health have been associated with obesity, including daytime napping, sleep timing, the variability of sleep timing, and low sleep efficiency. However, sleep duration is the most-studied for its impact on obesity.
  
  Sleep problems have been frequently viewed as a symptom of mental illness rather than a causative factor. However, a growing body of evidence suggests that they are both a cause and a symptom of mental illness. Insomnia is a significant predictor of major depressive disorder; a meta-analysis of 170,000 people showed that insomnia at the beginning of a study period indicated a more than the twofold increased risk for major depressive disorder. Some studies have also indicated correlation between insomnia and anxiety, post-traumatic stress disorder, and suicide. Sleep disorders can increase the risk of psychosis and worsen the severity of psychotic episodes.
  
  Sleep research also displays differences in race and class. Short sleep and poor sleep are observed more frequently in ethnic minorities than in whites in the USA. African-Americans report experiencing short durations of sleep five times more often than whites, possibly as a result of social and environmental factors. A study done in the USA suggested that higher rates of sleep apnea (and poorer responses to treatment) are suffered by children in disadvantaged neighborhoods (which, in context, includes a disproportionate effect on children of African-American descent).
  
  Sleep health can be improved through implementing good sleep hygiene habits. Having good sleep hygiene can help to improve your physical and mental health by providing your body with the necessary rejuvenation only restful sleep can provide. Some ways to improve sleep health include going to sleep at consistent times every night, avoiding any electronic devices such as televisions in the bedroom, getting adequate exercise throughout your day, and avoiding caffeine in the hours before going to sleep. Another way to greatly improve sleep hygiene is by creating a peaceful and relaxing sleep environment. Sleeping in a dark and clean room with things like a white noise maker can help facilitate restful sleep. However, noise except of white noise may not good for sleep.