Will hairs that are lost during combing grow back?

During laser comb therapy there can be shedding, you need to wait until the end of the therapy. if you experience shedding after the therapy you can have PRP, mezotheraphy, medication use or hair transplant depending on your situation. 

This needs an in-person evaluation. I suggest seeing a hair loss expert now to go over your condition and provide you information about your best treatment options. There are great non-invasive options like prp/progesterone which can help with hair regrowth and/or hair transplantation. See an expert. Best, Dr. Emer

Many women and men traumatize their hair with combing, brushing, coloring, straightening or pulling into ponytail or braids. All of these can result in breakage of the hair and if it occurs at the hair-skin junction can result in bald spots (alopecia). If the hair doesn't grow back within the next few months, do seek a professional opinion. Seeing a lot of hair in your comb, brush or shower can also be due to stress, changes in hormone status or development of a medical disorder like thyroid disease.
Choose a shampoo and conditioner that is gentle on your hair, consider supplements containing Biotin and be careful going forward with how you groom your hair. Platelet rich plasma (PRP) injections can be very helpful in enhancing the look of your hair.

Hair follicles cycle through growth and rest phases, so having hairs shed and come off when you comb is normal.  If you tug on your hair and pull it out repeatedly, eventually the follicle will stop working.

Provided you have no other hair and scalp issues, hair that is lost during combing will grow back. Combing simply extracts haors that were destined to come out anyway. If you have a scalp issue and hair loss condition, the above may or may not apply.