Humans spend about 1/3 of their lives sleeping. Sleep is a basic human need that serves to maintain and optimize bodily functions including, but not limited to, immune system, tissue healing, cardiovascular health, pain modulation, cognitive function, learning, and memory. Quality of sleep is recognized as an important health behavior, yet chronic sleep disturbances are reported in 50-70 million adults in the US. Due to the health consequences associated with sleep disturbances, The Centers for Disease Control and Prevention has deemed insufficient sleep to be a public health problem.

Sleep contributes to health problems through many different mechanisms, which we will discuss further.

Immune function and tissue healing:  Sleep deprivation leads to the formation of more pro-inflammatory immune cells, which can decrease the ability to fight illnesses and can also alter tissue healing mechanisms.

Pain Perception: There is a great deal of evidence suggesting that a decrease in sleep leads to increased sensitivity to pain. People with chronic pain often report a greater disturbance in sleep time, poor quality of sleep, delayed sleep onset, increased waking at night. Although pain is associated with sleep quality, many studies support a stronger relationship between the effects of lack of sleep on pain rather than the effects of pain on sleep. So, there is a strong suggestion that lack of sleep will cause increased pain.

Cardiovascular health: Shorter sleep duration’s (less than 5-6 hours per night) is associated with an increased risk of coronary heart disease and developing other cardiovascular conditions. The reason for this correlation is unclear, but often other factors such as low physical activity, depression, and obesity are seen in both those with cardiovascular conditions. These factors are present in individuals with sleep disturbance as well.

Depression and Anxiety:  About 75% of people with depression experience sleep disturbance and this is thought to be due to several mechanisms including the altered ability to regulate chemicals in the brain that affect sleep stages including arousal and emotional regulation.

Motor Skill Learning: Sleep enhances the ability to learn new skills. Those that sleep after task performance show better ability than those individuals that stay awake after learning a new task. Those that are sleep deprived perform worse on coordination activity.

Cognitive function: Although sleep likely impacts all cognitive functions, attention or ability to concentrate and working memory are the most studied. Sleep deprivation results in slower responses and increased mistakes. People with lack of sleep have slower ability to react to visual stimuli.

Mortality: An increased mortality rate is associated with poor sleep quality.  Healthy individuals who sleep less than 6 hours each night had a higher risk of death than those with 6-8 hours of sleep.

Impaired sleep impacts many aspects of health and thus should be prioritized to optimize health and reduce the risk of injury and disease. Visit https://sleep.org for more details about sleep and health.