An overnite stay in a sleep lab is how it is generally diagnosed. If you present to your doctor with certain symptoms, they will likely order one. Not every person will have the same symptoms. It can depend on the severity and longevity of the sleep apnea. Below are some commonly reported symptoms.
Not feeling rested even after enough sleep
Daytime sleepiness
Short term memory loss
Impaired cognition
Irriitability
Morning headaches
Waking up coughing or choking
Waking up short of breath
Waking up with fast heartbeat
Depression
Sexual problems
Increasing blood pressure
Increasing blood sugar
Snoring with breathing pauses