Hello. I had questions on the first steps to diagnosing either of these. My little sister (17) is showing possible signs (based on my research and friends who have thyroid problems) of either or both of these. My dad is being a jackass and just thinks she's fat. Here's her symptoms. I want to be able to present my case to try to force him to get her a diagnosing appt.

-cannot lose weight no matter what methods tried (dieting, exercising, etc)

-achy joints (may be a weight thing but seems to be a symptom also)

-indigestion with almost anything she tries to eat, no matter how healthy or small

-feels extremely fatigued

-periods are every 4 months (may be something else but could be relevant)

I'm afraid if she doesn't get it taken care of soon, she could stay very uncomfortable and/or become infertile. Any advice or experience would be nice. Thanks so much :)