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Does Hair Grow Back After Stress or Dieting?


According to the United States National Library of Medicine, the scalp of a human contains about 100,000 hairs and a person could lose up to 100 hairs per day. Both men and women may experience hair loss with age, however, it can also happen during dieting or periods of extreme stress.

Hair and Stress

Usually at any given time, around 90 percent of the hair on one’s head are in the growing phase and increase in length by a half- inch per month. This stage in the life cycle of a hair will usually last for about two or three years.

After that point in time, hair will typically go into a resting phase. The resting phase will sometimes last for up to three or four months before the hair will fall out and is replaced by a new one.

Sometimes, a significant event that brings on a lot of stress can spark something in the body that will result in a change in its physiological function and it can cause a large number of hairs to go into the resting phase simultaneously. These sorts of events can disrupt the normal life cycle of hair and it can be the body’s way of responding to stress, dieting or some other type of upset.


A variety of different stressors can result in hair loss. Things such as diet, hormonal fluctuations or an emotionally stressful event can cause a physiological imbalance in a person’s system and other stressors could include:
• Severe infection
• Major surgery
• A strict, low calorie diet
• Lowered estrogen levels
• Severe illness
• High fever
• Medications including birth control pills, retinoids and beta blockers

Crash Dieting and Hair Loss

As was previously mentioned, stress can be a culprit behind hair loss. Going on a crash diet is the worst thing a person can do to their body and any sudden or massive changes in the diet could lead to a negative impact on hair growth. However, the effects of an unhealthy diet may not show up for months, because when a person goes on a crash diet, the metabolism can slow down and in turn, so can hair growth. Dieting will likely only result in immediate hair loss as a result of stress caused by an extreme dietary shift.

If someone follows a low calorie or fad diet, it is likely to result in nutritional deficiencies. Be wary of a diet that has you consuming only one or two types of foods, because to remain healthy a person requires a variety of different vitamins, minerals and nutrients.

Will it Grow Back Again?

There is good news for those suffering from hair loss due to stress or extreme dieting, it can grow back. Once a source of stress is removed or an individual refrains from a crash or fad diet and resumes healthy eating habits, hair loss should resume within a short period of time. If you are concerned with hair loss, you may wish to visit your physician for further information.