50 yo male Hypothyroid and mild apnea and can't stay asleep, why? Wake up after 3 hrs. Been on Synthroid and TSH is now. 3, free T4 is 1.5. On CPAP also. No prob falling asleep so not a hygiene issue. Tried every sleep med, Melatonin and herb.

Many possibilities. There are multiple reasons why you can't stay asleep. The best starting point is to address your sleep hygiene. Start with making sure you have this list covered before looking at other factors. http://www.webmd.com/sleep-disorders/features/sleep-hygiene#1 If addressing these items doesn't help, then you may need to see a sleep doctor for a sleep study.