Advice please

Hello, I'm 19 years old, fit, I used to box and go to the gym before, I don't drink, I don't smoke, I don't drink soda. A friend of mine is in the hospital with kidney failure, and he just found out that he's on the transplant list, he's on dialysis, this thing really shocked me, and he's my age and I'm really shocked. I'm sorry to ask the following question, but what would be some ways to avoid this thing? Thank you very much for the answers and I apologize if I inconvenienced anyone.