With obstructive apnea, it's mostly hereditary. You inherit the shape of nose from your parents, why not the structures in your airway? Weight gain can make it

With obstructive apnea, it's mostly hereditary. You inherit the shape of nose from your parents, why not the structures in your airway? Weight gain can make it worse as those tissues also can expand, and any weight on your breathing can help turn a partial blockage into a full one. That weight can include muscle weight, and body builders often suffer from apnea. But the thing to keep in mind is that obstructive sleep apnea isn't so much a condition as a description of what's happening. Apnea means you stop breathing, obstructive means something is blocking it. Maybe it's because your fat belly is weighing you down, maybe it's your tiny nostrils and deviated septum, or maybe the back of your tongue is thick because your dad also had a thick tongue. That's not even including self-imposed factors like central nervous system depressants (alcohol) and smoking, both of which can make apnea worse. Ever notice how drunk people snore?