Overview

Idiopathic hypersomnia is an uncommon sleep disorder that causes you to be excessively sleepy during the day even after a good or prolonged night's sleep. It also often causes difficulty waking up after you've been asleep at night or for a nap. Naps generally aren't refreshing.

The need to sleep can strike at any time, including when you're driving a car or working, which makes idiopathic hypersomnia potentially dangerous.

The condition often develops over weeks to months. Diagnosing idiopathic hypersomnia requires ruling out more common sleep disorders. Treatment is aimed at controlling symptoms with medication.

Diagnosis

To diagnose your condition, your doctor will review your symptoms, go over your family and medical history, including your medications, and conduct a physical examination. Your doctor might order several tests to diagnose your condition, determine the cause of your condition and rule out other conditions.

• Epworth Sleepiness Scale. Your doctor may ask you to rate your sleepiness with this tool to help determine how sleep affects your daily life.
• Sleep diary. Your doctor may ask you to keep a sleep diary in which you log your daily sleep and wake times to help show your sleep amounts and pattern.
• Polysomnogram. In this test, you stay in a sleep center overnight. A polysomnogram monitors your brain activity, eye movements, leg movements, heart rate, breathing functions and oxygen levels as you sleep.
• Multiple sleep latency test. This measures your sleepiness and the types and stages of sleep you go through during daytime naps. This test is generally conducted the day after a polysomnogram.

Treatment

Because the cause of idiopathic hypersomnia isn't known, the treatment is aimed at easing symptoms. Stimulant medication, such as modafinil (Provigil), might be prescribed to help you stay awake during the day.

In addition, your doctor might recommend that you develop a regular nighttime sleep schedule and avoid alcohol and medications that can affect your sleep.