Obstructive sleep apnea, or OSA, is caused by a blockage in the airway due to relaxation of the muscles in the back of your throat. There are several factors that may increase your risk of sleep apnea, like being male and older in age. Additional factors include:
Excess weight
A narrowed airway
Neck circumference
Family history
Nasal congestion
Medical conditions
Smoking and use of alcohol
Certain medications