Help! I’m losing my hair and don’t know why!

May 5, 2020

Dr. Ashley Margeson

Dr. Ashley Margeson


Hair loss or hair thinning is one of the worst things to experience, especially when it seems to come out of nowhere. Although it’s common to lose a little hair when you’re in the shower or when you’re combing through, you know when what you’re losing isn’t normal. And while hair loss can cause anxiety, stress and hit our self esteem hard, it also can be a sign of some underlying issues. 

To start with, general hair thinning is different from Alopecia aerata, which is an autoimmune condition. This should be ruled out by your medical practitioner, along with the following non-autoimmune causes of hair loss. 

If you’ve recently had a baby, you might be experiencing postpartum hair loss (1-3). The most common hypothesis of this cause is the progesterone and estrogen drops that happens after giving birth. It is stressful, but don’t panic! Full hormone turnover takes about 3 months, so you should expect hair loss to even out after about 3 to 4 full cycles.

Another extremely common cause of hair loss in women is low iron (4-5). Iron anemia or insufficiency can cause hair loss, along with other symptoms like easy bruising, shortness of breath on exertion (like walking up the stairs or a hill!), heavy periods and cold hands and feet. 

Finally, long term stress and high stress situations can trigger hair loss due to a variety of reasons (6-8). Divorce, a new job, exams, moving and illness of yourself or a loved one can all have an effect. The primary reason is that high cortisol causes a decrease in progesterone (one of the systemic hormones that causes hair to grown in pregnancy), which triggers hair loss – but only after about 3 months! High stress situations also trigger a change in your thyroid hormones through something called the Ovarian-Adrenal-Thyroid Axis; this can cause hypothyroidism, or peripheral hypothyroidism (where your TSH is ok, but your T4 can’t convert to T3), which can cause hair loss along with a multitude of other symptoms. 

Phew! That’s a lot of causes, so if you’re experiencing hair loss and it seems like it’s come out of nowhere, talk with your health care practitioner about how these causes could be factors! 



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Kantor J, Kessler LJ, Brooks DG, Cotsarelis G. Decreased serum ferritin is associated with alopecia in women. J Invest Dermatol. 2003;121:985–988.

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Kasumagić-Halilović E. Thyroid autoimmunity in patients with alopecia areata. Acta Dermatovenerol Croat. 2008;16:123–5.

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