Hello,
You are having ," Male pattern baldness" (Androgenetic alopecia). Generally onset is in fourth decade of life. In your case, its important to find the reason behind early onset for alopecia (hair loss). various reasons behind early onset male pattern baldness are:
1.genetics: family history( father or mother side ) if hair loss
2. stress: physical or mental
3. long term illness: typhoid, fever
4. improper nutrition like lack of esssential nutrients in diet
5. chronic problem like
thyroid
6. cosmetic hair treatments like straightening, hair colour
so, kindly correlate with above mentioned causes in your case.
Also, its recommemded to send your scalp picture : front, back and top view. This will help me in :
1. Analyzing your baldness grade
2. hair type
so, that we can suggest you treatment options