What is the difference between gpt, sgpt and alt? my blood test says i have a gpt is 51 with an upper limit of 40? is this something to worry or normal? i read up to 50 is considered normal but lab says 40 is normal?

They measure different aspects of liver and other organ's health. I would use the lab's normal values. I would go to Wikipedia and read about them. For greater detail go to uptodate.com, pay a bit, and read all about them. They will have tables to help you understand what each one measures and what diseases make them go up and/or down. Then discuss with the Dr who ordered them and knows u.

As mentioned earlier your question has been answered multiple times. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines