Lack of Donor Hair?

How common is it for a patient to be lacking in donor hair when needing a transplant? I hear a lot about issues of lack of donor hair and I was wondering if the majority of significantly balded patients actually face this problem.

The great majority of men have a good donor supply (I’d guess in the 99% range). The question that needs answering is — how does the supply balance against the needs for the hair based upon the degree of balding?

In men, under 1% have a condition called diffuse unpatterned alopecia (DUPA) where the donor supply and much of the recipient supply is poor, because of medical and/or genetic conditions. Documenting the presence of DUPA is critically important before a hair transplant is done, or the results will be a failure and the donor area becomes scarred.