Hair Falling off 4 Years After Hair Transplantation (FUE) Procedure

The most likely reason your transplanted hair is falling out is Telogen Effluvium.  This is a temporary condition caused by something stressing the follicles and should abate once you are relieved of the stress.  

The other possible cause of this hair loss would be unlikely, but perhaps the grafts were harvested from donor hair which was located too high in the back of the scalp, in an area which was prone to the effects of DHT or other permanent hair loss factors.  If the only hair you are losing is the transplanted hair, then this is possibly the cause, although it would be difficult to determine.

This can be a frightening and confusing thing for patients to see. Depending on your age and stage of hair loss at the time of your surgery, there are a lot of possibilities for what could be going on. In most patients, 4 years after surgery what is usually seen are the native (non-transplanted) hairs falling out. That is a natural progression of hair loss. However, in some patients the genetics of hair loss is so strong that some of the hairs from the donor area were destined to fall out. Often times these are hairs that were taken from lower down on the back of the scalp, near the neck. Some patients have receding hair loss here (but it recedes UP the scalp there instead of BACK like on the hairline). Other medical issues could also be also have developed since your original surgery that can cause problems in the skin and thereby cause hairs to fall out (autoimmune conditions or hormonal imbalances). The first step would be to see your original surgeon or another experienced hair specialist to get proper guidance. Hope this helps!

I suggest you to see your hair specialist and have a general check up, and get your hormones checked as well. 

Dear 34male
Thanks for the question. If necessary, hair transplant can be repeated 3-4 times depending on the density and the number of the hair follicles on the donor site.
A second hair transplant can be planned in cases of continuing rapid hair loss, with patients who desire a high density of hair, for the purpose of providing a hairy scalp on those sites where no prior transplantation has been done, and for the purpose of correcting the outcome with those patients who have had an unsuccessful hair transplant in some other clinic. I wish you all the best.

Hair loss after transplantation can occur for a variety of reasons.  First of all, hair loss which was harvested from the proper location can ultimately be lost.  For this reason, proper surgical planning can be helpful to only harvest hairs which will not be susceptible to androgenic alopecia.  In addition, some patients may have other factors to their hair which can contribute to hair loss which need to be properly evaluated.  Hair loss is a complex medical and surgical problem which requires specialized attention to achieve appropriate results.

We have been performing hair transplants now for over 20 years. It would be my opinion that this is very unusual.
I would suggest going back to the MD that treated you and let them examine.
I would want to see what your hairs look like under magnification. If I see miniaturization, I would begin treating with Laser to kick start the hairs back to the growth phase.