I am 18 yrs old.but i don't have energy and feel week from the age of 15 as compared to my friends. i m 5"11. weight is 80 kg. plz help as it embarases?

See your doctor.: This is a situation where it would really make sense to see your physician for an evaluation. Questions to answer before you go; have you had any significant weight gain or loss, any change in your menstrual period, any change in your diet, are you sleeping well. Could be many things but best figured out with complete history and exam.

Get to the Doctor: This is first, not common. Second, it is time to stop wondering and to get in for a full evaluation. I would be concerned about thyroid conditions or diabetes. Go to see your family doctor. Take notes with you so that you do not forget all of your symptoms or your concerns.