The Surprising Reason You Can’t Stay Awake

Getting verrrry sleepy? Your insatiable need for zzz’s could indicate an underlying chronic condition, according to researchers. Here’s what to know.

by Lara DeSanto Health Writer

Are you yawning through the day despite a full night’s sleep? That’s excessive daytime sleepiness—and according to a new study, it could mean you’re at an increased risk of certain health conditions.

Older people with excessive daytime sleepiness may be at increased risk of things like cancer, diabetes, and high blood pressure, says a new Stanford study of 10,030 adults. Of the participants, 34% were 65 and older.

"Paying attention to sleepiness in older adults could help doctors predict and prevent future medical conditions," said study author Maurice M. Ohayon, M.D., of Stanford University in Stanford, California. "Older adults and their family members may want to take a closer look at sleeping habits to understand the potential risk for developing a more serious medical condition."

Excessive daytime sleepiness—aka hypersomnolence—can also seriously disrupt your life. Think about it, how much harder is it to function at work or other activities when you’re feeling exhausted every day?

The study results found that those who reported daytime sleepiness had a 2.3 times higher risk of getting diabetes or high blood pressure three years later compared with those who didn’t experience hypersomnolence. And they were twice as likely to get some sort of cancer. Additionally, in a second interview of the participants, those who reported sleepiness were 50% more likely to have certain musculoskeletal and connective tissue diseases, like arthritis, tendinitis, and lupus. Yikes. Researchers were careful to account for gender and sleep apnea when stating their results, too.

Excessive Daytime Sleepiness: Things to Know

Excessive sleepiness affects about 20% of the population, according to the National Sleep Foundation. In fact, it’s the most common reason why people seek treatment at sleep clinics. It’s not the same thing as fatigue, which is more related to low energy and a need to rest—but not necessarily sleep.

On its own, excessive sleepiness isn’t a disorder—it’s actually a symptom itself. But what does it look like? Per the National Sleep Foundation, people with excessive sleepiness feel drowsy or sluggish on most days, and it may negatively impact work, relationships, schooling, or other daily activities.

Some common causes of excessive sleepiness include the following, according to the National Sleep Foundation:

  • Poor sleep habits (like not getting enough sleep or having an erratic sleep schedule)

  • A sleep disorder, such as sleep apnea or insomnia

  • Certain medications of which excessive sleepiness can be a side effect

  • Other underlying medical conditions

If you are feeling super sleepy, see your doctor—they can help you come up with a plan to get you on track to feeling rested again. Just be prepared as they may refer you to a sleep specialist as well for further testing.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at