I am 15 years old and have amenorrhea . I had a period a few times about two years ago, but it was spotty and irregular. Now, I have no period at all. About one year ago, I trained for a triathlon and neglected to eat enough and lost some weight. I am fairly certain that the weight loss caused the lack of menstruation . However, I realized the problem and added calories to my diet. I love to cook and eat and now feel that I am at a healthy weight. I am 5 feet 6 inches and weigh 114-117 lbs, depending on the time of day. I eat a healthy, balanced diet and exercise regularly but not excessively. My question is: Why do I still have no period? I have been at a healthy weight for about 8 months now but still no period. What should I do to get it to return, or should I just wait for it to start? My mother didn t start her period until she was 16 years old--could genetics be playing a part? Please give me some advice...Are there longterm health problems that will occur to me from this amenorrhea? Thank you.