Well about a month ago I had my 4th knee surgery. Ever since this last surgery I couldn't sleep past 3am no matter what time I go to bed. The lack of sleep in the first few weeks were because of pain and having to sleep on my back. The last week I haven't had much pain and sleep in normal positions, but I still cannot sleep past 3am. I wake up at 3am everyday and watch the world series of poker on espn then go back to sleep around 5am and wake up at 630 to go fishing. Is this just habitiual at this point? I slept good one night since surgery and that was because I was hammered. The lack of sleep is starting to wear on me. Should I go to a sleep study or a doctor?

Sounds like your body clock got set to wake you up at 3 each morning.

The best bet?  Check with your doctor.

He/she should be best able to instruct you on what will "reset" your body clock.

If pain woke you up, and you took meds to relieve it, your body can develop a dependency for that med.  If it got used to receiving its "fix" at three in the a.m., it will wake you, just as hunger can wake us in the morning.

Doctor first.  He will know if a sleep study is in order.

You might want to try some melatonin first.  It's available in the drug dept at most pharmacies.  It's a naturally occuring compound already in the body that aids in sleep.  Sometimes our levels get out of wack.  It's relatively cheap.  Sometimes it works, sometimes not.  Might be worth a shot.  

Get up and fish!  

Early awakening insomnia, usually lasts for a little bit and could be from pain meds.

I've been that way following my two surgeries.  Anesthesia really kicks my butt for several weeks/months following.   Sleeping habits are whacked, as well as my normal thought processes, etc.  Like Rhino said it sounds like your bio clock is messed up.  Have you tried any OTC sleep aids for a few nights (not more than a week or so)?  These might keep you asleep past three a.m. and allow you to get a full night's rest and your body back into its old habits.  It is always a good idea to contact your Dr. or his/her nurse to get some advice.  More than likely they'll want to see you, but if you have good insurance, it might be worth 25-35$ co-pay to assure you that you are on the right track.

Definately check with your doctor. Some things he will ask is do you snore, do you wake up frequently, does your bed partner say you seem to "stop breathing" while sleeping, leg movements, etc. You've already stated you're tired during the day. Also, do you have high blood pressure or any history of heart disease? All are symptoms to or are related to sleep apnea. Google "sleep apnea" and see if any of your symptoms fit so when you see your doctor, you'll know what to ask him and what he'll ask you. Good luck.

Sounds like you need to get hammered more often.

You're getting more sleep than I am.  Up about midnight regardless of bedtime, out the door about 3 or so for snook fishing ( got 4 and a tarpon today)home about 10, then in and out the rest of the day bass fishing.

My wife wants to kill me, but I love it, always managed on 4 hours a sleep a day.