Obstructive sleep apnea (also called simply “sleep apnea”) is a common sleep disorder in which a person wakes at night, sometimes numerous times, but is not aware of it.

Sleep apnea has been linked to many cardiovascular health problems, including high blood pressure, heart disease, congestive heart failure, and atrial fibrillation.

To those conditions, you can add sudden cardiac death. A five-year study of 10,700 people found that sleep apnea raises the risk of sudden cardiac death independently of other factors. Doctors suspect this is because such abnormal sleep patterns may trigger heartbeat arrhythmias. Sleep apnea may also increase inflammation and unhealthy changes in blood vessels.

Though it’s often thought of as a disorder that affects men, sleep apnea can occur in women as well. In fact, an autopsy report linked sleep apnea to the death of actress Carrie Fisher in 2016.

Symptoms of sleep apnea include:

• Loud snoring

• Stopping breathing during sleep (observed by others)

• Daytime sleepiness

• Fatigue

• Drowsy driving

• Waking up short of breath

• Waking up frequently at night, without known cause such as a need to urinate.

If you have symptoms of sleep apnea, ask your doctor for a referral to a reputable sleep clinic, most often found at a university medical school.