In addition to obesity, other anatomical features associated with obstructive sleep apnea -- many of them hereditary -- include a narrow throat, thick neck, and round head. Contributing factors may include hypothyroidism, excessive and abnormal growth due to excessive production of growth hormone (acromegaly), and allergies and other medical conditions such as a deviated septum that cause congestion in the upper airways.
In adults, smoking, excessive alcohol use, and/or the use of sedatives is often associated with obstructive sleep apnea.