How to stop hairfall?

Alopecia : Alopecia or hair loss can be due to a variety of factors. Simple measures that can be taken to thicken hair include taking a multivitamin and eating foods rich in biotin, zinc and iron. If there are also rashes in the scalp, treating them with medicated shampoos may help. Checking thyroid hormone levels and other labs is advised. Finally, products such as rogaine (minoxidil) may help. See a dermatologist also.

Hair Loss: To stop hair fall one has to determine the cause. If you have a telogen effluvium which is where the hair is shedding, then treatment is with B12 shots every month. If you have male pattern hair loss which is genetic there is the oral Propecia and rogaine (minoxidil) for men. Other causes include medications, infections, hormonal abnormalities, thyroid disease and others.

Depends on cause...: One's primary care doctor can check for medical causes. If none are found, then one can see a dermatologist, especially one specializing in hair restoration (some treatments: minoxidil, finasteride, hair transplants...). Medical causes may include hormonal problems (low thyroid), seborrhea, alopecia areata, stressful illness. Other causes: genetic male/female pattern baldness, telogen effluvium...