Insomnia seems to be the granddaddy of all sleep problems. But what about people who sleep too much or those who constantly feel sleepy even when they get “normal” amounts of sleep?

What’s new: Some researchers are now finding that excessive sleepiness is more prevalent than previously thought—perhaps affecting up to 5% of American adults.

The average adult sleeps roughly six to nine hours a night. If you get this amount of sleep or more but still feel sleepy during the day—and/or you remain sleepy after a 20-minute nap or need multiple naps that interfere with your daily activities—a medical condition could be the cause.

Excessive sleep and daytime sleepiness are common symptoms of dozens of health problems, including hormone disorders (such as thyroid disease)…depression…nutritional deficiencies (including low vitamin D or iron levels)…and medication side effects from such drugs as painkillers, antidepressants and antihistamines. That is why people who are concerned about sleeping too much or feeling sleepy during the day should consult their primary care doctors.

However, if you are generally healthy but are still sleeping too much, you could have hypersomnia. With this sleep disorder, a person will typically sleep a full night but will be unrefreshed and sleepy throughout the day.

Possible causes of hypersomnia…


If you go to sleep earlier than most people and wake up hours before you’d like, your body clock probably needs resetting.

Patients with ASPD are typically exhausted and ready to sleep in the early evening (around, say, 7 pm) and wake up at 2 am or 3 am. Even though they sleep the normal six-to-nine hours, their body clocks have advanced by several hours.

Warning signs: Suspect ASPD if you have the above symptoms for more than a week.

Diagnosis: In most cases, a sleep specialist can diagnose ASPD by learning about your sleep schedule (usually from a sleep diary you keep to record your regular sleep patterns).* Actigraphy, in which the patient wears a small sensor on the wrist to help the specialist identify sleep patterns, may also be used. The patient can wear the sensor in his/her own home.

Treatment: You can reset your body clock with bright-light therapy. This involves sitting near a light box (available online and at some pharmacies for about $60 to $200) for one to two hours in the early evening before bedtime. The full-spectrum light mimics sunshine and delays the release of melatonin, a sleep-inducing hormone.

Some individuals can achieve a normal sleep-wake schedule (for example, 10 pm to 6 am) within a month or less. Others need to use a light box for longer.

Consult your doctor before using a light box. It may not be appropriate if you have certain eye conditions, such as glaucoma or cataracts. Also, work with a sleep specialist who can advise you on the proper time to use the light box. Insurance may not cover the cost of this therapy—check with your insurer.


This is a neurological disease that interferes with the brain’s ability to control sleep-wake cycles. It causes sudden, and irresistible, bouts of daytime sleepiness. For example, patients may nod off in the middle of a conversation or while eating. Patients who don’t have such sleep attacks still can be chronically sleepy even if they think they are sleeping at night (with narcolepsy, frequent nighttime awakenings disturb normal sleep).

Warning signs: Narcolepsy is often accompanied by episodes of cataplexy, a sudden loss of muscle tone while awake, which leaves the patient unable to move or speak.

Diagnosis: Patients have an overnight sleep test (polysomnogram) to identify abnormalities. In a second test (multiple sleep latency), a patient takes a series of five naps spaced two hours apart. People with narcolepsy will sleep during most or all of the nap periods…will fall asleep in eight minutes or less…and will enter REM sleep soon after falling asleep.

Treatment: Medications can target the predominant symptoms of narcolepsy. Examples: Sodium oxybate (Xyrem) helps control cataplexy and sleep attacks…zolpidem (Ambien) or other sedatives are helpful for those who mainly suffer from disturbed sleep…and modafinil (Provigil) is a stimulant that reduces daytime sleepiness and can minimize sleep attacks. Sometimes several drugs are prescribed at the same time. Patients usually need to take them long term, but symptoms tend to subside with treatment.

Lifestyle changes, such as limiting caffeine, scheduling naps and managing stress, are also helpful.


If you kick and twitch while you sleep, you’ll want to sleep more during the day. Patients with PLMD usually are not aware of their nighttime limb activity (unless someone tells them). The main symptom is daytime sleepiness. The leg jerks cause frequent, brief awakenings and interfere with deep sleep—in patients and their bed partners.

Warning signs: Most people with restless legs syndrome (RLS)—uncomfortable sensations that can be relieved only by moving the legs—also have PLMD. PLMD is also linked to narcolepsy and other sleep disorders.

Diagnosis: An overnight sleep test measures the frequency and severity of leg movements and detects any other sleep disorders.

Treatment: Medications that block abnormal muscle movements and improve sleep. These include pramipexole (Mirapex), clonazepam (Klonopin) and sometimes a narcotic medication.


Snoring, snorting or gasping for breath during sleep are some of the widely known symptoms of sleep apnea, but daytime sleepiness is also a red flag for the condition.

Patients with apnea stop breathing for anywhere from just a few seconds to more than a minute—a cycle that interrupts their sleep. Apnea is dangerous because it increases risk for dementia, high blood pressure, heartbeat irregularities and other cardiovascular diseases.

Warning signs: In addition to sleepiness during the day, people with sleep apnea may wake up with a dry mouth and a headache from diminished oxygen.

Diagnosis: If you experience chronic daytime sleepiness or your bed partner says that you snore or gasp for breath while sleeping, you may have sleep apnea. (If you sleep alone, you can record yourself at night.) A sleep study is used to confirm the diagnosis—it measures your breathing patterns and blood oxygen levels.

Treatment: A positive airway pressure (PAP) device. Used at home, it supplies a constant stream of air into the nose/mouth while you sleep. PAP can often eliminate the interrupted breathing patterns of sleep apnea and daytime sleepiness. For those who can’t tolerate PAP devices, an oral appliance or a small device placed in each nostril can be used as an alternative, but it may not work in all patients. There are surgical treatments for sleep apnea, which are beneficial in about 50% of cases.

Also helpful: Weight loss. Most apnea patients are overweight. In these cases, losing as little as 10% of one’s body weight often can help.

Note: Though uncommon, some people have positional sleep apnea (they have it only when sleeping on their backs). If this is the case for you, training yourself to sleep on your side may help (try putting a tennis ball in the pocket of a T-shirt worn backwards). A sleep specialist can tell if your sleep apnea is related to sleep position.

*To find a sleep specialist near you, consult the American Academy of Sleep Medicine,