Who is recommended for hair loss treatment? Should I start now?

After washing my hair, I notice the hair falling out, and I’ve started to feel self-conscious about the crown of my head. I’m not sure if it’s serious yet, but I feel like I should start managing it proactively, so I’m looking into who is recommended for hair loss treatment. What symptoms are typically used to determine eligibility for treatment? Would it be advisable to see a doctor if my hair becomes thinner or falls out more than usual? It is difficult for me to determine on my own if I qualify for treatment, so I am curious about the tests and consultations conducted at hospitals. I would like to know how to distinguish between cases where scalp care alone is sufficient and those requiring medical treatment. If I do qualify, I am also wondering if starting treatment early is beneficial. Since costs and treatment durations likely vary depending on the method, are there any specific things I must check during the initial consultation? I want to identify the exact cause rather than worrying alone based solely on information found online. I would appreciate any experiences and advice from those who have received treatment in person.