What causes sleep apnea if one os not overweight and has no history. tmj, clenching, stiff neck muscles, psychiatric medication?

Sleep disorder: Obstructive sleep apnea is commonly associated with obesity. However, central sleep apnea can be seen in a person with completely normal weight. Most of the times the cause of central sleep apnea is obscured and could not be found. This can be seen in patients using certain pain medications and others suffering from brainstem function problems (ie. Chiari malformation-congenital).

Several factors.: Sleep apnea can happen in people who are not overweight so if you are tired all of the time, have acid reflux, high blood pressure, or diabteic talk to yor doctor about having a sleep study. If you are tired even though you have slept enough time, call your doctor.

Sleep Apnea: Its the airway structure which is narrow can cause osa without obesity.

Two kinds : There are two forms of sleep apnea obstructive which is most often caused by obesity or airway abnormalities. And central which is due to your central nervous system disrupting your sleep patterns. Consult a sleep specialist.

All or none: I have seen many patients for an oral mouthpiece for sleep apnea that are not overweight. A thorough screening and health history with a sleep professional is required to hopefully rule out some of the other causes.

Many factors: Obstructive vs central sleep apnea. Different disease, different causes. See sleep specialist for sleep studies.