Not getting enough sleep - sometimes by choice - is the most common cause of excessive sleepiness.

Damage to this region, scientists have found, causes excessive sleepiness.

First, there are those who complain of excessive daytime sleepiness.

Talk with your doctor if you continue to have excessive sleepiness even while taking modafinil.

Insomnia can cause excessive daytime sleepiness and lack of energy.

In many patients, this can lead to insomnia and excessive daytime sleepiness.

But for some people, excessive sleepiness actually gets in the way of daily work, childcare, and even leisure activities.

Excessive sleepiness and unrecognized sleep disorders are common problems among police officers, a new study reports.

Continued behaviors are causing significant family disruption or excessive daytime sleepiness.

Some try to cope with excessive sleepiness through caffeine or stimulants, he says.