It seems like your hair fall
might be due to male pattern baldness
or androgenetic alopecia. It is basically a hormonal as well as genetic condition. You do not need to go for DHT test. At earlier stage, it can be treated with topical therapy like minoxidil
and oral drug finesteride. However as the baldness progresses, these therapies might not work. In advanced cases of baldness, mesotherapy with PRP, minoxidil, stem cells can be tried. In mesotherapy, drugs are directly instilled in hair follicle through micro needles. If nothing works, surgical hair transplantation
is the best choice. So basically to understand what will work best for you,an appointment with dermatologist
needs to be fixed. Take care.