Is Severe Hair Loss A Symptom Of Hypothyroidism?

Good morning, thank you for your time.I have a grand daughter age 19 who has had weight problems all of her life. She exercizes regularly, swimming, coaching water polo teams and hockey. She alo watches what she eats all the time. Leah has had blood tests and drs have said they show she does not have a thyroid problem. The girl is beside herself. We have a strong family history of hypothyroidism, with one sister losing all her hair by the time she was diagnosed as having a problem, and another being diagnosed with the problem. I was diagnosed with it when I was 14 yrs by a dr at a hospital I visited for another illness and was sent for a I think the name of the test was Basal Urea Breath Test which indicated that I had hypothyroidism. No Dr will listen to my test being available now, they it is used only for finding the pylori bactor problem. Sorry I cant remember the whole name. Can you assist.