Sleep Apnea  

If you think you have sleep apnea, talk to your doctor and he will refer you for a sleep study to determine if you have it. I was diagnosed with severe sleep apnea which was resolved with a CPAP. Flew for 10 years with sleep apnea. Special issuance from the FAA. Never had an issue. Took a little while to get the special issuance when I applied but after that no biggie. AOPA was helpful when I transitioned from the military to the FAA medical certification.

If you have sleep apnea - get treatment. Sleep apnea can cause several serious medical issues, like a stroke. That's a 2 year grounding (maybe permanant if these is damage) and getting your medical back is super expensive.