Other than obesity, is sleep apnea a symptom of any other underlying conditions?

Is Insomnia ( the fall asleep type) a symptom of apnea?

I know stay asleep is what about fall asleep? I just got diagnoses and trying to see whats caused what

Is a swollen floor of the mouth a symptom in sleep apnea?

at first my floor of my mouth was swollen and still is and now also my tongue and throat are swollen. My speech is impeded and the outside of my neck under the chin area looks swollen and now I have sleep apnea symptoms too and will be going to a sleep clinic.

If this is a symptom of Centralized sleep apnea, what underlying disease could it be?

# If other symptoms, including difficulty swallowing, voice changes of body weakness or numbness, this may indicate an underlying disease that is affecting the nervous system.