Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Hair Loss

Expected Duration

How long hair loss lasts depends on the cause. In telogen effluvium, for example, hair usually is lost over several weeks to months, but then grows back over the next several months. When hair loss is a side effect of a medication, hair growth usually returns to normal once the drug is stopped. If you are losing hair because of abusive hairdressing, the hair loss usually stops after you change to more natural styling, except in traction alopecia, which results from years of pulling the hair back in tight braids. In tinea scalp infection, the fungus that causes the problem must be treated for at least 6 to 12 weeks and hair regrowth may be slow. Early treatment is important in preventing possible permanent hair loss. Both male- and female-pattern baldness tend to get worse over time but can be treated.