Obstructive sleep apnea is one common cause of excessive sleepiness. In obstructive sleep apnea, the airway becomes blocked during sleep, causing the person to wake up in order to breathe. This can happen hundreds of times each night, but often the person is unaware of the frequent awakenings, because they are brief. It’s estimated that between 5 and 20 percent of the adult population suffers from obstructive sleep apnea.
If you are excessively sleepy and have a history of snoring or disturbing your partner at night, or you are overweight, obstructive sleep apnea may be the cause of your sleepiness. To understand more, talk to your doctor and consider undergoing a sleep study. Sleep studies gather information about your sleep patterns overnight and can sometimes be done at home. Additional causes of excessive sleepiness include, but are not limited to insomnia, depression, shift work, and narcolepsy.