People with sleep apnea have pauses in their breathing, or breathing becomes shallow, while they're asleep. This can happen for a few seconds to a few minutes at a time and up to 30 times during an hour of sleep.
Deep sleep can be jolted into light sleep during these breathing pauses. Sleep quality suffers and people with sleep apnea are consequently tired a lot.
It's not unusual for people to suffer from sleep apnea and not be aware of it. A partner will likely be the one who notices something isn't right.
Obstructive sleep apnea is the most common sleep apnea. Central sleep apnea occurs less frequently. Some people can have a combination of obstructive sleep apnea and central sleep apnea.
This causes problems for the brain and body because it can reduce oxygen levels in the bloodstream.
Overweight people may have an obstruction because of the extra weight.
https://www.empowher.com/sleep-apnea/content/sleep-apnea-makes-good-nights-sleep-impossible-dream