Excessive sleepiness is the feeling of being especially tired or drowsy during the day. Unlike fatigue, which is more about low energy, excessive sleepiness can make you feel so tired that it interferes with school, work, and possibly even your relationships and day-to-day functioning.

In a poll by the American Sleep Foundation, 18 percent of respondents reported experiencing excessive sleepiness. But the percentage may actually be much greater.

The key to overcoming excessive sleepiness is to determine its cause. There are several sleep-related problems that need to be evaluated before a diagnosis of IH can be given.

Any condition that keeps you from getting good quantity and quality sleep at night can cause excessive sleepiness during the day. Daytime sleepiness may be the only symptom you know, but other signs, such as snoring or kicking, may be occurring while you’re asleep.

For many people with sleep disorders, it’s a bed partner who observes other key symptoms. Regardless of the cause, it’s important to have your sleep condition evaluated if daytime sleepiness is keeping you from making the most of your day.

Among the more common causes of excessive sleepiness are:

Sleep apnea

Sleep apnea is a potentially serious condition in which you repeatedly stop and start breathing throughout the night. It can leave you feeling sleepy during the day.

Sleep apnea also has several other symptoms. Some of them include:

Sleep apnea can also contribute to high blood pressure and other heart problems, as well as type 2 diabetes and obesity.

There are actually two main types of sleep apnea. They can both cause excessive sleepiness because they keep you from getting enough deep sleep during the night. These types of sleep apnea are:

Restless legs syndrome

Restless legs syndrome (RLS) causes an irresistible and uncomfortable urge to move your legs. You may be lying down peacefully when you start to feel a throbbing or itching sensation in your legs that only gets better when you get up and walk. RLS makes it difficult to fall asleep, resulting in excessive sleepiness the next day.

It’s not clear what causes RLS in some cases, though it may affect up to 10 percent of the U.S. population. There may be a genetic component, while other research suggests low iron may be to blame. Many scientists also believe that problems with the brain’s basal ganglia, the region responsible for movement, are at the root of RLS.

Narcolepsy

Narcolepsy is an often misunderstood sleep problem. Like RLS, it’s a neurological disorder. With narcolepsy, the brain doesn’t regulate the sleep-wake cycle properly.

During the night, a person with narcolepsy will awaken multiple times (much like insomnia). Then during the day, they’ll have episodes of excessive daytime sleepiness at inappropriate times. People with narcolepsy may even fall asleep in the middle of a conversation or during a meal.

Narcolepsy is fairly uncommon, probably affecting fewer than 200,000 people in the United States. It’s often misdiagnosed as a psychiatric disorder. Anyone can have narcolepsy, though it usually develops in people between the ages of 7 and 25.

Depression

A noticeable change in your sleep schedule is one of the more common symptoms of depression. When you develop depression, you may sleep much more or much less than you used to.

If you aren’t sleeping well at night, you’re likely to experience excessive sleepiness during the day. Sometimes sleep changes are an early sign of depression. For other people, changes in sleeping habits occur after other signs appear.

Depression has many potential causes, including unusual levels of certain brain chemicals, issues with the regions of the brain that manage mood, and traumatic events.

Medication side effects

Some medications cause drowsiness as a side effect. Medications that commonly include excessive sleepiness include:

If you think your prescription medication is making you sleepy, talk with your doctor before you stop taking it.

Aging

Studies have shown that older people spend the most time in bed but get the lowest quality of sleep. According to the study, sleep quality starts to decline in middle-aged adults.

As we age, we experience less time in the deeper types of sleep and wake up more in the middle of the night.

Idiopathic hypersomnia

If you can’t determine a secondary cause to your excessive sleepiness, you may have idiopathic hypersomnia (IH), which is a chronic neurological sleep disorder. It causes excessive sleepiness despite adequate or even long periods of sleep.

“Idiopathic” is a term for an unknown cause, as the cause of IH isn’t currently known. People with IH struggle to wake up despite setting multiple alarms, and they may have difficulty getting out of bed.

The treatment options for excessive sleepiness vary greatly, depending on the cause.

Obstructive sleep apnea

One of the most common treatments is continuous positive airway pressure (CPAP). This therapy employs a small bedside machine that pumps air through a flexible hose to a mask worn over your nose and mouth.

Newer versions of CPAP machines have smaller, more comfortable masks. Some people complain that CPAP is too loud or uncomfortable, but it remains the most effective OSA treatment available. It’s typically the first treatment a doctor will suggest for OSA.

Restless legs syndrome

RLS can sometimes be controlled with lifestyle changes. A leg massage or a warm bath before bedtime may help. Exercising early in the day may help with RLS and with your ability to fall asleep.

Your doctor may recommend iron supplements if it appears your iron levels are low. Your doctor may also prescribe medications to control RLS symptoms. If so, be sure to discuss any potential side effects with your doctor or pharmacist.

Narcolepsy

Narcolepsy symptoms may be treated with some lifestyle adjustments. Brief, scheduled naps may help. Sticking to a regular sleep-wake schedule every night and morning is also recommended. Other tips include:

  • getting daily exercise
  • avoiding caffeine or alcohol before bedtime
  • quitting smoking
  • relaxing before bed

All of these things can help you fall asleep and stay asleep better at night. This may help cut down on sleepiness during the day.

Depression

Treating depression can be done with a combination of therapy, medications, and lifestyle changes. Antidepressant drugs aren’t always necessary. If your doctor recommends them, they may be needed temporarily.

You may be able to ease depression through talk therapy and making certain lifestyle changes, such as exercising more, limiting alcohol, eating a nutritious diet, and managing stress.

Age-related sleep problems

The lifestyle changes that can help treat narcolepsy and insomnia can also help people experiencing age-related sleep problems. If lifestyle changes alone aren’t enough, talk with your doctor. They can prescribe sleep medications that can improve your quality of sleep.

Idiopathic hypersomnia

Since the cause of idiopathic hypersomnia isn’t known, treatment is focused on alleviating symptoms and may include stimulants, diet changes, or lifestyle changes.

Getting enough sleep is crucial to good health. If you can identify the cause of your excessive sleepiness and get treatment, you should find yourself feeling more energetic and with a better ability to concentrate during the day.

If your doctor doesn’t ask about your sleep routine, volunteer your symptoms of daytime sleepiness and discuss ways to overcome them. Don’t live with feeling tired every day when you might have a condition that’s easily and safely treated.

If you don’t already have a primary care specialist, you can browse doctors in your area through the Healthline FindCare tool.