According to the Centers for Disease Control and Prevention (CDC), around 15.3 percent of women and 10.1 percent of men regularly feel very tired or exhausted in the United States.

Tiredness can cause an array of problems. For example, around 1 in 25 adult drivers report falling asleep at the wheel each month. About 72,000 crashes and 44,000 injuries each year are a result of drowsy driving, and that’s not to mention the estimated 6,000 fatal crashes caused by drowsy drivers.

Everyone feels tired at some point in their lives — whether it’s due to a late night out, staying up to watch your favorite TV show, or putting in some extra hours at work. Often, you can put your finger on the reason you’re not feeling your best, but what about those times when you can’t pinpoint the cause of your tiredness? What makes you feel tired then?

Medical News Today have researched the possible explanations for why you could be feeling so drained and the steps that you can take to feel re-energized.

1. Lack of sleep

A lack of sleep may seem an obvious reason for feeling tired, yet 1 in 3 U.S. adults are consistently not getting enough of it.

Tiredness increases the risk of accidents, obesity, high blood pressure, depression, and heart disease.

People aged between 18 and 60 years need 7 or more hours of sleep every day to promote optimal health, according to The American Academy of Sleep Medicine and the Sleep Research Society.

Getting under the recommended hours of sleep each night is not only associated with fatigue, impaired performance, and a greater risk of accidents, but it also has adverse health outcomes. These include obesity, high blood pressure, depression, heart disease, stroke, and an increased risk of death.

If you struggle to fit in 7 hours of sleep, here are some tips to help you achieve a full dose of much-needed slumber:

• Maintain a consistent sleep routine. Try to go to bed at the same time every night and get up at the same time each morning — even on the weekends.
• Avoid naps. We need a certain amount of sleep within a 24-hour period and no more than that. Napping reduces the amount of sleep that we require the following night, which might lead to difficulty getting to sleep and fragmented sleep.
• Limit time awake in bed to 5–10 minutes. If you find that you are lying awake in bed worrying or with your mind racing, get out of bed and sit in the dark until you are feeling sleepy, then go back to bed.
• Ensure that your bedroom is quiet, dark, and a comfortable temperature. Any light that enters your room could disturb your sleep. Ensure that your room is dark and that light emitted from digital devices is out of sight. Cooler room temperatures are considered better to promote sleep than warmer temperatures.
• Limit caffeinated drinks. Try not to consume caffeinated beverages after noon. The stimulating effects of caffeine can last for many hours after intake and cause issues with initiating sleep.
• Avoid tobacco and alcohol before bed. Smoking cigarettes and drinking alcohol before going to bed may cause fragmented sleep.

If you practice all the sleeping habits listed above and still wake up tired, it might be a good idea to contact your healthcare provider and discuss whether you have a sleep-related medical problem such as insomnia, obstructive sleep apnea, or restless legs syndrome.