Common Causes of Hair Loss

Common Causes of Hair Loss

It is normal for people to shed up to about 100 hairs per day. Losing more than this? Are you noticing more hair on your pillow, hairbrush, or shower drain? There are actually many possible explanations for this.

The root cause of hair loss may be simple and reversible but could also signal an underlying health issue. Listed below are some of the more common causes of hair loss.

Physical or emotional stress

Shocks to your body such as severe illness, surgery, delivering a baby, and sudden weight loss can disrupt the hair’s life cycle and promote increased shedding of hair.

This goes for emotional stress as well– for example, divorce, death in the family, or caring for an ill family member.

Hair loss related to stress manifests about three to six months following the event. The hair should grow back normally once the body recovers.

Male pattern baldness

This is very common and obvious. About two-thirds of men will experience hair loss by age 60. This is due to genetics and male hormones. The classic presentation is hair loss in the front of the head and at the temples.

Some topical and oral medications can help halt further hair loss (such as Rogaine). You can also have surgery to transplant new hair.

Thyroid dysfunction

Thyroid disorders are very common, particularly in women as they get older.

Hyperthyroidism is an overproduction of thyroid hormone causing your thyroid to be overactive. This can cause increased loss of hair.

On the other hand, hypothyroidism is an underactive thyroid. Underproduction of thyroid hormone can cause hair and nails to become more brittle and break easier.

Thyroid disorders are diagnosed by a blood test. If you are concerned, see your provider.


Excessive use of hot tools (curling iron, flat iron, hair dryer) can cause hair to become more brittle and break. Try to use them less often and use a heat-protectant spray.

If you do a lot of tight hairstyles like pigtails or braids, then hair loss related to traction alopecia can result. Be careful because these styles can actually affect the root of the hair, causing the hair to not grow back.

Autoimmune disease

Alopecia areata is an autoimmune disease in which the body mistakenly targets the hair as foreign resulting in hair loss.

This condition can be treated by steroid injections or medications. The course of the disease can be very unpredictable. This should be treated by a dermatologist.


Hair loss is a common symptom of anemia caused by iron or vitamin B12 deficiency. Other symptoms include paleness, dizziness, and fatigue. This is diagnosed by a blood test.

The symptoms should resolve with a supplement.

Lack of dietary protein

Hair loss can result about two to three months after a drop in protein intake. Good sources of protein include meat, fish, and eggs. Vegan or vegetarian? You can still get adequate amounts of protein from foods such as beans and legumes.

Medication/supplement side effect

Some medications used to treat high blood pressure, depression, and other conditions can cause hair loss.

Speak with your provider to see if any of the medications you take cause hair loss. He or she may consider changing the dose or switching the medication altogether.

Too much vitamin A supplement is also associated with hair loss. Check to see how much you are getting from your multivitamin or supplement– 5,000 International Units (IU) is adequate for adults and children over 4 years of age.


Unfortunately, it is quite common for women to experience thinning of hair in their 50s and 60s. We are not totally sure why this happens.

There is no specific treatment recommended for this. Speak with your hairdresser regarding tips and tricks to keep your hair healthy and shiny.

Polycystic ovarian syndrome (PCOS)

PCOS is excess amounts of male hormones in women which can lead to hair loss. This can also cause unwanted hair on the face, chin, and abdomen.

PCOS is often treated with birth control pills to regulate male and female hormones which should improve symptoms.

This is not an all inclusive list but there are many causes of hair loss! If you are concerned, be sure to see your provider to assess for an underlying cause.

Disclaimer: Information contained in this post should not be substituted for medical advice. If you think you are having a problem, contact your own provider who knows your health history.

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