The second most common cause of non-scarring hair loss in women is Telogen Effluvium, or the “outflow of resting hairs”. This refers to the hairs that are shed on a regular basis, but in excess of the normal amount. We have, on average, about 100,000 hairs on our heads. Those with blonde hair typically have the most hair, closer to 150,000 hairs, but finer in texture, whereas redheads have the least hair, closer to 90,000 hairs. Between 85-90 percent of the hair on your head are in the growing, or anagen, phase, and will not come out easily when you pull your hair. The rest of the hair, 10-15 percent, is mostly in the resting, or telogen, phase, and are easily removed during normal hair brushing. A small percentage are in a transitional phase called catagen. Typically, most people who wash their hair every day will lose fewer than 100 hairs per day. Those who wash less frequently will notice significantly more hair lost on the days the hair is washed due to the additional manipulation of the hair. Furthermore, a small shift in the growth phase of the hair can produce a startling amount of hair loss. Rest assured, you will not go bald due to telogen effluvium.
So what causes Telogen Effluvium? This type of hair loss is usually associated with a significant event that has occurred approximately 3 months prior to noticing the increase in hair shedding, or perceived hair loss. These events include illnesses such as the flu or Covid-19, with high fever, major surgery, dieting/weight loss, anemia, thyroid disease, physical and psychological trauma, and childbirth. All of these events cause the body to slow its metabolism in order to conserve energy for the healing process it anticipates will occur. Hair and nail growth are two of the body’s most energy-requiring processes, and while they are important aesthetically, they are expensive to the healing body.
There are few laboratory tests that will make the diagnosis other than the clinical exam and perhaps a skin biopsy to exclude other causes of hair loss, however, basic studies to ensure that there is no underlying iron deficiency or thyroid disease are reasonable. Most of the time, routine blood work has already been performed in the recent past by your primary care physician that can be reviewed. Any abnormalities should be investigated and corrected. Telogen effluvium typically resolves within 6 months, often sooner, as the old telogen hairs are being replaced by new anagen hairs as the telogen hairs are falling out. Unfortunately, it takes 3-6 months to be able to appreciate the new shorter hairs that are growing in and covering the scalp. As I stated earlier, you will not go completely bald due to telogen effluvium.
In the next post, I will discuss treatment of telogen effluvium in the context of balanced nutrition and dietary supplements.