Question:

I am sleepy most of the day. I get 7-8 hours of sleep a day. However, I can fall asleep at any time. As soon as I sit down and relax, I am asleep within 5 minutes. It doesn`t matter where I am. I only feel rested for the first couple of hours of the day. Could this be some sort of sleep disorder?

Answer:

It is obvious that this sleepiness is a problem for you and you are right to seek advice. Excessive daytime sleepiness (EDS) has many causes and there are a number of possible causes to consider. These can be broadly categorized into primary sleep disorders and problems that can affect your sleep that are not sleep disorders per se.

The most common cause of EDS is that individuals have insufficient total sleep time or a lack of adequate sleep. Not sleeping enough hours (a condition called sleep restriction) is can lead to excessive sleepiness during the day and is easily fixed by increasing your sleep time. From your question, it appears that you are probably getting enough sleep, though keep in mind that some individuals may need more than 8 hours per night to feel adequately rested.

In terms of sleep disorders, there are conditions that fragment your sleep during the night such that the sleep quality is poor and this can lead to daytime sleepiness. The most common of these sleep disorders is obstructive sleep apnea (OSA). This is a condition where the upper airway behind the tongue and soft palate is narrowed so that when the person falls asleep, the airway may partially or completely close off. An arousal from sleep can result from either the effort to breath or if the oxygen level drops as a result of the reduced airflow. These arousals can occur recurrently throughout the night which results in poor quality sleep and thus daytime sleepiness. Those at risk for OSA tend to be overweight, have a thick neck size (17 inches or greater in males and 16 inches in females), male gender, and those over the age of 60. However, individuals not meeting these criteria can have OSA as well. There is often a history of loud snoring during sleep, choking or gasping at night, witnessed apneas (bed partners see the lack of breathing), and unrefreshing sleep. OSA is diagnosed with an overnight sleep study (polysomnography).

Another sleep disorder that causes sleepiness is called narcolepsy. This is a condition where a person may sleep through the night although commonly, people with narcolepsy say they will initially fall asleep fast but keep waking up during the night. They may or may not feel refreshed when they wake up but become sleepy again a few hours later. Naps may help the person feel refreshed. There are other symptoms that may go with this condition such as sleep paralysis (person wakes up with a sensation that they can’t move), hypnagogic hallucinations (seeing images from dreams as one is falling asleep) and cataplexy (muscle weakness or loss of muscle tone with extreme emotions – particularly laughter). Narcolepsy is diagnosed with a sleep study where you sleep overnight (polysomnography) and then stay for a series of naps the next day (multiple sleep latency test or MSLT).

A third sleep condition is called idiopathic hypersomnia. This is a condition where one sleeps all night but does not feel refreshed on awakening and dozes off during the day. Naps are typically not refreshing. This too needs to be diagnosed with a PSG and MSLT.

Aside from these conditions, numerous other factors may influence the quality of your sleep. These can range from the environment you sleep in (i.e. too warm, too loud) to your other medical problems (i.e. heartburn or breathing problems) to medications you may taking. Fragmented sleep from any of these conditions can lead to daytime fatigue and sleepiness. Depression can also cause people to feel sleepy during the day and needs to be considered.

As you can see, there are a number of possible explanations for your symptoms and it would best to undergo a thorough evaluation to determine how best to proceed. You should probably discuss this problem with your primary care physician first and then seek the opinion of a Sleep Specialist if needed.

For more information:

Go to the Sleep Disorders health topic.