my 18 year old son has complained of being thirsty a lot. We are fairly sure it is not diabetes, because my youngest son is Diabetic Type 1 and we have tested the older son with his blood test kit and it was normal. I am concerned that my son has damaged his kidneys because of taking too many supplements as he is a rugby player. We are going to the GP tomorrow, but would like your opinion. He is in very good health otherwise.
Hi and welcome to Chat Doctor.  As a Urologist, I can understand your anxiety. His thirst maybe due to his rugby exercises. As there's a family history of diabetes, its always safer to confirm in the lab. Do the following tests, to clear your doubts about kidney damage also.1. Urine routine and ACR.2. Blood routine, FBS,HbA1C,creatinine, LFT and platelets.3. Ultrasound scandium. According to the reports, an expert opinion can be given. Chat Doctor.  Manga.