When you find yourself feeling exhausted even after just waking up from hours of sleep, you might already be suffering from a sleep disorder and not be aware of it. Many dismiss the morning fatigue as normal, but the truth is that the body is naturally programmed to feel recharged after getting enough rest, so feeling sluggish in the morning could be an indication of an underlying health problem.

Sleep quality is an important element to proper daily functioning. Sleep itself is made up of four stages that must be gone through for it to be considered complete. Throughout the cycle, the body releases different substances and hormones that help restore health and regulate metabolic functions. If it is interrupted or altered, it could mean serious consequences for the body beyond just feeling sleepy and tired the rest of the day.

There are nearly a hundred types of sleep disorders, the most recognizable and common among which include narcolepsy, sleep apnea, restless leg syndrome (RLS) and insomnia.

Obstructive sleep apnea is said to be the most common sleep problem in the U.S., affecting more than 20 million adults. A person with OSA is often observed to “stop” breathing for 10 to 20 seconds at a time and snore loudly due to a blockage in upper respiratory airways. This could happen when your tonsils are enlarged, the tongue falls back into the throat, or the adenoids are inflamed. OSA attacks can happen hundreds of times at night during sleep and this is why a person can wake up feeling extremely tired.

RLS is a neurological problem characterized by an uncontrollable urge to move the limbs or legs. Some people report pain in the legs or crawling feelings, that’s why they need to keep it moving. The levels of discomfort can range from simply irritating to painful, thereby disrupting sleep. Those diagnosed with RLS said it is difficult for them to fall asleep and stay asleep because of the sensations.

Narcolepsy has a notorious image because of how it’s portrayed in many Hollywood comedies, but it’s actually a pretty common sleep disorder. Those with this problem are unable to complete the four cycles needed for quality sleep and often immediately head to the REM stage, or actual sleep stage. This is why some people often find themselves suddenly dozing off in the middle of an important activity. Because the body has not been able to go through all the phases, it ends up feeling so tired and exhausted upon waking.

The best way to address feelings of being sleepy and tired is to have yourself checked by a doctor to rule out any serious medical conditions. Common sleep disorders are typically easily corrected with the right medication, environment, diet or therapy. It’s important that you receive the right interventions to ensure that you don’t end up with a worse situation than before.

In this image, a woman sleeps at Gatwick Airport in southern England, Dec. 7, 2013. CARL COURT/AFP/Getty Images