High AST, normal ALT

Hello Doctor and others,
I recently had a comprehensive metabolic panel test performed and my doctor found out that my AST level was somewhat high (78) (normal is 2-50 U/L). My ALT level was 50 (normal is 2-60 U/L) so, that one was fine. My Alkaline Phosphatase was normal (55) and my glucose was normal too (95). My doctor reccomended a second, sole AST test but I'm wondering why it was high in the first place. I work out 2-3 times a week (but I hadn't worked out in 2 days when I had the blood test done). Also, I do not drink much except 1-2 beers (at most) a week. I do not use drugs and never have used needles. I have have some lower back pain but it can be just sore muscles as well and I do have some abdominal pain and flank pain but that too may be due to working out those muscles or from past surgery or from my own mind-induced pain. I had surgery to open a urethral stricture about 6-7 months ago but I doubt it is related to the high AST level. What are you thoughts? I'm a 25 year old male who has no other known problems. I'm worried it may be hepatitis (from unprotected sexual contact) though I do not have any other symptoms. If it isn't that, I plan on taking more precaution next time and getting the HEP A & B vaccine. My father and brother both have hypothyroidism but I display none of those symptoms and I'm actually pretty thin.
I unfortunately have a nervous nature and I have looked it up on the internet and found many possibilities all of which are pretty scary. It's hard not to worry when you are told something is abnormal.
Thank you for your help with this!

[Kevin Pho, MD]

Most common causes of isolated AST level would be alcohol use.  I would abstain for alcohol and repeat the test to see if it improves.  If it continues to be elevated, you may want to consider a hepatitis screen and a liver ultrasound (to evaluate for fatty liver or other anatomical abnormality).  

If everything is negative, I would periodically observe the level to ensure it isn't rising.  It isn't high enough to warrant a liver biopsy.  

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Thanks,
Kevin, M.D.