What to Know About Excessive Daytime Sleepiness

Excessive daytime sleepiness (EDS) is the urge to sleep when you normally expect to be awake and alert. This condition is measured with these methods:¹

• Epworth Sleepiness Scale - a questionnaire that measures your likelihood of falling asleep in routine situations
• Multiple Sleep Latency Test - an objective measure of how quickly you fall asleep at different times of day
• Maintenance of Wakefulness Test - an objective measure of your ability to stay awake over a certain time period

Sometimes people mistake excessive daytime sleepiness for fatigue. Fatigue is tiredness or lack of energy. It does not include the urge to sleep.²

What causes excessive daytime sleepiness?

Excessive daytime sleepiness  is a common symptom among people with narcolepsy. Research has found that it affects about 12 percent to 65 percent of people with obstructive sleep apnea (OSA). Narcolepsy is a chronic (long-term) disorder of the nervous system. OSA occurs when your throat muscles relax and block your airway so that you briefly stop breathing over and over during sleep.^1,3-6

OSA’s disturbed sleep and lack of oxygen may make excessive daytime sleepiness, fatigue, and altered attention among the most common symptoms. Researchers found that the risk of excessive sleepiness from OSA is the same as the risk from sleeping less than 6 hours per night. Even after treatment for OSA, you may continue to have excessive daytime sleepiness.^1,7

Other risk factors for excessive daytime sleepiness include:^1,8

• Depression
• Extremes of age
• Female gender
• High caffeine consumption
• Limb movement disorder
• Narcotic painkillers
• Night work, shift work, and intense work schedules that limit time for sleep
• Obesity
• Over-the-counter sleeping pills
• Poor sleep habits
• Serious disease, such as heart failure, lung disease, and cancer
• Use of television and cell phones in bed

How does excessive daytime sleepiness impact daily life?

Excessive daytime sleepiness can limit your safety and your ability to work, travel, and enjoy events. If you are sleepy during the day, you may have an increased risk of the following:¹

• Anxiety
• Depression
• Decreased memory and thinking ability
• Decreased creativity
• Decreased vigilance
• Disturbed attention
• Headaches
• Lower energy
• Longer reaction time

The factors listed above may lead to the following:¹

• Decreased quality of life
• Higher rate of absenteeism
• Increased errors
• Lower work productivity
• Poorer time management
• Poorer interpersonal relationships

The most dangerous effects are accidents while at work or driving. Excessive daytime sleepiness is an important risk factor for car crashes. Research has found that excessive daytime sleepiness is linked to increased outpatient and hospitalization costs, because of accidents. The accidents are more likely to be fatal because of the sleepy driver’s failure to brake before impact.^1,9,10

If you believe you have excessive daytime sleepiness, it's a good idea to talk with your doctor.