Can I add density to zone A with a second hair transplant?

First I would suggest you to wait 1 year to pass from your first operation. After that your donor area can have a better recover. If not you can use your beard or chest hair as your donor. 

Hair density depends on several factors, please see below. Density is one of the most critical factors after hair transplantation.  Early on you may not be able to fully determine your density.  Density depends on various factors including the number of hairs  per cm squared, the thickness and vibrancy of hair, direction and design of hair.  Techniques for density vary from surgeon to surgeon.  In my office, we utilize a specialized technique that allows for optimizing density and found it to be helpful. Best, Dr. Anil Shah

You can add always add density with hair grafting but to understand the results and realistic outcomes you need to consult with a doctor in person.

What can be done depends on the quality of your donor site and the size of the defect that you want to cover it is quite hard to discuss it without seeing your pics. I do a lot of secondary hair transplants both after FUE and FUT procedures . They are usually successful in some cases we do body hair transplants (if scalp donor is not available)

The average person (with normal donor density), has at least 6000 grafts in the permanent /donor zone from which to extract.  Depending on the size of your first FUE, let's guestimate 2000 grafts were moved.... that would leave about 4000 more. Thus, undergoing a 2nd FUE is possible without the donor looking depleted.  Consider adding photos to your next inquiry.We often do revision transplants from other surgeon or 2nd transplants to add greater density and fine tune the first FUE.

A great first step would be an online consultation. Often you can submit photos to top hair restoration surgeons for a complimentary evaluation and assessment. This should help lead you in the right direction. Having multiple consultations with different doctors will let you know your best options. 

Secondary procedures can help to fill in the areas of lower density from a primary procedure.  The number of grafts we are able to obtain after an initial procedure can be determined through a consultation.  This depends on your donor hair density and the number of grafts used in the initial procedure.

We find patients extremely satisfied when they have a 2nd FUE to fill in gaps and add density. The only way to know is to come in for a free in-person consultation and we will discuss your surgical and nonsurgical options. We have an office nearby you in metro St. Louis.  Looking forward to meeting you. 

If you had a hair transplant and you are asking if you can have another in the same area, the answer is yes