In today's fast-paced world, a good night's sleep has become somewhat of an indulgence. It has fallen down our list of priorities behind work, chores, social time, and entertainment. But sleep should not be a luxury. It’s a vital part of life as important to your physical and mental health as food and water.

Studying the need for sleep is a relatively new research field. Scientists are looking into what happens to the body during sleep and why the process of sleep is so essential. We do know that sleep is necessary to:

  • maintain critical body functions
  • restore energy
  • repair muscle tissue
  • allow the brain to process new information

We also know what happens when the body doesn't get enough sleep. Sleep deprivation can cause a range of mental and physical problems, including impaired ability to:

  • think clearly
  • focus
  • react
  • control your emotions

This can result in serious problems in the workplace and at home. Chronic sleep deprivation has been shown to increase the risk for serious health conditions such as diabetes, cardiovascular disease, obesity, and depression, according to the Society for Cardiovascular Angiography and Interventions. It can also affect your immune system, reducing your body's ability to fight off infections and disease.

Think of a sleep-deprived body as a car with a flat tire. The car is running, but it’s moving slowly with fewer capabilities and less power. The longer you drive in that condition, the more you'll damage the car.

There are two main types of sleep: rapid eye movement (REM) sleep and non-REM sleep. Non-REM sleep is divided into four stages that range from light sleep to deep sleep. All stages of sleep are important, but deep sleep and REM sleep are the most critical. It’s during these stages that the important restorative functions of sleep take place.

Despite the importance of sleep, the average American adult sleeps fewer than seven hours per night. An estimated 50 to 70 million U.S. adults have a sleep or wakefulness disorder, according to the Centers for Disease Control and Prevention. These disorders include:

Our sleep habits change as we age. The National Institutes of Health say the average adult needs approximately seven to eight hours of sleep per night. School-aged children need at least 10 hours per night, and teens need nine to 10 hours per night.

But sleep assessment is not just about quantity. Sleep quality is equally important.

Many people with sleep disorders sleep an adequate amount of time but do not reach a deep enough stage of sleep to feel well-rested and refreshed in the morning. Waking up frequently in the night can also prevent you from reaching the critical stages of sleep.

To some, sleep comes as naturally as blinking or walking. For others, getting enough quality sleep is a major challenge that requires lifestyle changes or medical intervention. There are numerous reasons for sleep problems, ranging from short-term stressors to serious, long-term sleep disorders. If you have chronic sleep problems, talk to your doctor about finding a solution and about treatment options.