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Your Thyroid May Be Causing Your Hair Loss: Here's How

By Zawn Villines
Medically Reviewed by Jennifer T. Haley, MD, FAAD on November 18, 2020
A problem with your thyroid could be causing your hair loss, even if you have no other symptoms.

If you’re seeing more hair than ever before stuck in the drain or your hairbrush, you may begin to worry that you’re losing your hair. Hypothyroidism is a fairly common cause of hair loss, and hypothyroidism-related hair loss can also be reversible.

“A blood test to rule out thyroid abnormalities should always be a part of the diagnosis for hair loss due to medical conditions,” Abraham Armani, MD, a hair-restoration surgeon and hair loss specialist in Dallas, Texas, tells WebMD Connect to Care. 

According to the American Academy of Dermatology, it is normal to lose 50 to 100 strands of hair per day. If your hair is thick or long, a few dozen strands might look like a large clump, even if the number of hairs you’re losing is completely normal. But what if you are losing your hair?

What Does Your Thyroid Have to Do With Your Hair? 

Hypothyroidism occurs when the thyroid does not produce enough thyroid hormone. It is ten times more common in women, though men may also develop an underactive thyroid as well. 

According to Armani, thyroid hormones help regulate metabolism, heart rate, and your overall mood. It also affects the rate at which the body uses oxygen and energy, which can also affect hair and nail growth. This type of hair loss is called telogen effluvium. When this process occurs, hair that is in the growing stage (anagen) enters the resting and shedding stage, called telogen. Hair may stay in this stage longer than normal, causing more hair to fall out as less hair grows. 

An overactive thyroid, Armani warns, can also cause hair loss. So it is important not to self-medicate. People with thyroid disorders need ongoing treatment and regular thyroid monitoring. 

According to the National Institute of Diabetes and Digestive and Kidney Diseases, some other signs that a person may have hypothyroidism include: 

  • Fatigue
  • Unexplained weight gain 
  • Trouble getting or staying pregnant
  • Depression 
  • Frequently feeling cold, including cold hands and feet
  • A slow heart rate
  • Swelling in the neck
  • Dry skin 
  • Constipation 
  • Muscle and joint pain 
  • Puffy face
  • Irregular or heavy periods 

Sometimes hair loss is the only or first symptom of hypothyroidism. 

Get Help Now  

Addressing hypothyroidism early is important for preventing serious health problems. Giving attention to your hair loss sooner rather than later can stop your hair from thinning and may help to reverse any hair loss damage.