The medical term for hair loss is alopecia. Hair loss is commonly considered a men’s health topic (two thirds of all males can expect some hair loss by age 60), but women make up 40 percent of all hair loss sufferers. In thenormal cycle of hair growth, it is natural to lose up to 100 hairs per day. If you are losing more than that, or if parts of your scalp are becoming prominent, it could be a sign of excessive hair loss. The most common type of hair loss is called androgenic alopecia, which is an inherited tendency to stop producing new hairs. In women, this is referred to as female pattern hair loss.
Each hair follicle produces a single hair that normally grows about a half inch per month for about 4 to 6 years. It then goes into a resting phase and loses the hair before growing a new one. The number of hair follicles entering the resting phase is equal to the number of hair follicles starting the growth phase, so the number of hairs on the head remain the same. With androgenic alopecia, an increasing number of hair follicles never recover from the resting phase, resulting in a scalp with less hair. This loss of active hair follicles may take place over months or years before it is noticeable. Although androgenic alopecia occurs in both men and women, the pattern of hair loss is different. Instead of the receding hairline of male pattern baldness, in women the hair becomes thinner over the whole scalp, and the frontal hairline is usually spared. Other causes of hair loss in women include:
Constant pulling from hair that is tightly pulled back in a ponytail, bun, braids, weaved hair extensions, cornrows, or dreadlocks (Traction Alopecia)
Hormonal changes, such as pregnancy, menopause, or low thyroid hormone (hypothyroidism). Many women notice hair loss about 3 months after they’ve had a baby. This is due to high levels of pregnancy hormones that keep the hair follicles from entering the resting phase. When the hormones return to pre-pregnancy levels, a large number of hair follicles enter the resting phase all at once. This results in a significant numbers of hair falling out at one time. After a few months, the normal cycle of growth and loss starts again.
Alopecia areata, an autoimmune disorder that attacks the hair follicles, shrinking them and inhibiting hair growth
Medications that can damage hair follicles, such as chemotherapy or blood thinners