Graying of hair at this age can be due to multiple factors, mainly it is genetically determined. Other causes can be metabolic,
vitamin deficiencies, etc. We need to evaluate and find out the possible cause.
Average daily hairfall is 100-150 and anything more than that needs attention. Usually in males thinning at this age is due to male pattern hair loss. In addition there can be other causes like nutritional, stress, etc.
Next Steps
Read my article on routine Hair care
Health Tips
Consult qualified dermatologist who will do proper assessment and write necessary blood tests based on which your treatment plan can be decided for best possible results.All the best.