• A lack of sleep can lead to many health issues.

• In the short-term, sleep deprivation can reduce memory and learning ability, increases your risk for harmful accidents, and lead to poor judgment.

 • Long term, not getting enough sleep may increase your risk for heart disease, harm your mental health, and make it more difficult to lose weight.

• This article was medically reviewed by Alex Dimitriu, MD, psychiatrist, and founder of Menlo Park Psychiatry and Sleep Medicine. For optimal health, adults need at least seven hours of sleep each night.

Here are 6 ways a lack of sleep can negatively impact your health:

1. Impair your mental health: Insufficient sleep can affect your mood and increase your stress levels. In fact, people with insomnia are 17 times more likely to develop clinical anxiety than people who aren't sleep deprived. Non-depressed people who have insomnia may be twice as likely to develop depression as people who sleep well. In addition, research has found that 65% to 90% of adults with depression have sleep problems. While a lack of sleep can affect your mental health, depression can also cause insomnia, leading to a vicious cycle.

 2. Reduce memory and learning ability: Researchers have found that just five hours of lost sleep in a 24-hour period can cut off the connection between neurons in the hippocampus, the area of the brain associated with memory. A lack of sleep may also impair the brain's ability to flush out beta-amyloid, a toxic protein in the fluid between brain cells that have been linked to memory loss and Alzheimer's disease. "Not sleeping enough at night will make it more difficult for you to learn or remember things later," says Raman Malhotra, MD, a sleep medicine physician and associate professor of neurology at Washington University School of Medicine. "Sleep helps imprint memories or things you are studying to try and remember in the future."

3. Make it more difficult to lose weight: Not getting seven to eight hours of sleep each night can activate your body's endocannabinoid (eCB) system, which increases your appetite for pleasurable but unhealthy foods, like candy and chips. In addition, if you're not getting enough sleep, you may feel fatigued and not have the energy to exercise regularly, which can also contribute to weight gain. A small study of 15 healthy men, published in the American Journal of Clinical Nutrition in 2009, found that fewer hours of sleep for two nights in a row resulted in significantly decreased daytime physical activity.

 4. Increased risk of heart disease: Getting less than seven hours of sleep each night can increase your risk of heart disease, heart attack, or stroke regardless of your age, weight, and whether or not you smoke or exercise, according to the National Sleep Foundation. High blood pressure, or hypertension, is one of the major risk factors for heart disease. While you're getting a good night's sleep, your blood pressure should decrease by about 10% to 20%, which is known as nocturnal dipping. But if you don't get the sleep you need, your blood pressure won't dip at night. A consistent lack of sleep can also affect your body's ability to regulate stress hormones, and this chronic stress may contribute to a heart attack over time.

5. Cause harmful accidents: Driving while drowsy is similar to driving under the influence. It slows down your reaction time and awareness of hazards and reduces your ability to pay attention to what you're doing. According to a study published in the journal Sleep in 2018, drivers who had fewer than four hours of sleep in the preceding 24-hour period were 15.1 times more likely to be responsible for a car crash than drivers who slept seven to nine hours during the same period. The bottom line the adverse health effects of a single sleepless night can usually be mediated if you get better consistent sleep over the next few nights, Malhotra says.

However, if you've been experiencing a chronic lack of sleep over multiple weeks, months, or years, you may be at great risk of health problems that are more difficult to reverse. Some sleep disorders, like insomnia or sleep apnea, will require medical treatment in order to fully resolve your sleep issues.

If you think you are not getting enough sleep, consult with a physician or sleep specialist who can discuss treatment options.