Facts about normal hair growth
About 90% of hair on the scalp grows continually. In fact, each hair grows for about 2 to 6 years. The other 10% of scalp hair is in a resting phase that lasts 2 to 3 months. At the end of the resting stage, this hair is shed.
Most people have around 100,000 hairs on their head, and shed 50 to 100 hairs a day. This is normal. When a hair is shed, it is replaced by a new hair from the same follicle and the growing cycle starts again. Scalp hair grows about half an inch a month.
As people age, the rate of hair growth slows.
What causes hair loss?
Hair loss is believed to be primarily caused by a combination of the following:
Change in hormones
Family history of baldness
Untreated ringworm of the scalp
Vitamin A excess
Protein or iron deficiency
Rapid weight loss
Certain autoimmune diseases
Certain cancer treatments
Hair pulling due to trichotillomania
However, hair loss is not caused by the following:
Poor circulation to the scalp
Generally, the earlier hair loss begins, the more severe the baldness will become.
What is hair replacement surgery?
There are a number of hair replacement methods available. But hair replacement surgery can't help those who suffer from total baldness. Candidates for hair replacement must have a healthy growth of hair at the back and sides of the head. The hair on the back and sides of the head will serve as hair donor areas where grafts and flaps will be taken.
There are 4 different types of hair replacement methods, including the following:
Hair transplantation. During hair transplantation, the surgeon removes small pieces of hair-bearing scalp grafts from the back or sides of the head. These grafts are then relocated to a bald or thinning area.
Tissue expansion. In this procedure, a device called a tissue expander is placed underneath a hair-bearing area that is located next to a bald area. After several weeks, the tissue expander causes the skin to grow new skin cells. Another surgery is then needed to place the newly expanded skin over the nearby bald spot.
Flap surgery. Flap surgery is ideal for covering large balding areas. During this procedure a part of the bald area is removed and a flap of the hair-bearing skin is placed onto the bald area. This is done while the flap of the hair-bearing skin is still attached at one end to its original blood supply.
Scalp reduction. Scalp reduction is done to cover the bald areas at the top and back of the head. This method involves removing the bald scalp with sections of the hair-bearing scalp pulled together filling in the bald area.
Possible complications linked to hair transplantation procedures
Possible complications linked to hair transplantation procedures may include the following:
Patchy hair growth. Sometimes the growth of newly placed hair has a patchy look, especially if it's placed next to a thinning area. This can often be corrected by additional surgery.
Bleeding or wide scars. Tension on the scalp from some of the scalp reduction techniques can result in wide scars or bleeding.
Grafts not taking. Occasionally there's a chance that the graft may not take. If this is the case, surgery must be repeated.
Infection. As with any surgical procedure, there is the risk of infection.
About the procedure
Although each procedure varies, generally, hair replacement surgeries follow this process:
Location options may include:
Surgeon's office-based surgical facility
Outpatient surgery center
Anesthetic options may include:
Local anesthesia combined with a sedative (so you are awake but relaxed)
Average length of procedure. Several surgical sessions are usually needed to achieve satisfactory fullness, with a healing interval of several months recommended between each session. It may take up to 2 years before seeing the final result with a full transplant series.
Recuperation period. Plugged or grafted hair falls out within a month or 2 after surgery. This is normal and almost always temporary. After hair falls out, it generally takes another month or more before hair growth resumes. A surgical touch-up procedure may be needed to create more natural-looking results after the first incisions have healed. This may involve blending. This is a filling-in of the hairline using a combination of minigrafts, micrografts, or slit grafts.
Nonsurgical hair replacement with medicine
Finasteride. Finasteride treats male pattern baldness. It is available in pill form by prescription only. It works by blocking an enzyme called 5-alpha reductase. This enzyme changes the male hormone testosterone into a stronger form called DHT (dihydrotestosterone). It's believed that DHT is a key factor in male pattern hair loss. Finasteride lowers DHT levels in a man's scalp. This slows hair loss and promotes hair growth.
Dutasteride. Dutasteride is another medicine that blocks the formation of DHT and may also help hair growth.
Minoxidil. Minoxidil is available as an over-the-counter medicine. It is approved for both men and women. It is a topical solution that must be applied by applicator or fingers to the balding area twice a day, every day. Reducing the dosage to once a day results in some hair loss. Stopping the medicine causes you to go back to your pretreatment baldness. Minoxidil is available in a women's strength and a men's strength.
Always see your healthcare provider for more information.
February 21, 2018
Treatment of androgenetic alopecia in men, UpToDate
Berman, Kevin, MD, PhD,Image Reviewed by Staywell medical art team.,Sather, Rita, RN