Blood Tests for Female Hair Loss Causes: An Informative Guide

Hair loss in women can be a distressing experience, affecting confidence and emotional well-being. While often associated with men, many women experience it due to factors ranging from genetics to hormonal imbalances and nutritional deficiencies. Understanding the underlying causes is crucial for effective treatment. A physician or dermatologist will often recommend several blood tests to identify any contributing medical conditions or deficiencies.

Common Causes of Hair Loss in Women

Before delving into blood tests, it's important to understand the common causes of hair loss in women:

Androgenetic Alopecia: Also known as female pattern hair loss, this is the most common type, often related to genetics and hormonal imbalances. It typically presents as thinning hair at the top of the head or widening hair partings and is often seen in those suffering from PCOS and women who have gone through menopause.
Telogen Effluvium: This condition occurs when a large number of hair follicles enter the resting (telogen) phase, causing excessive shedding. It is a temporary condition which causes shedding from all over the scalp and can be triggered by emotional or physical stress, including hormonal changes and dietary imbalances as well as being a side effect of certain illnesses and medications, including contraceptive pills.
Alopecia Areata: An autoimmune condition where the immune system mistakenly attacks hair follicles, leading to patchy hair loss.

The Role of Blood Tests in Diagnosing Hair Loss

Blood tests are essential in diagnosing the underlying cause of hair loss, allowing healthcare providers to develop targeted, effective treatment plans.

1. Complete Blood Count (CBC)

A complete blood count (CBC) measures different components of your blood, including red and white blood cells, hemoglobin, and platelets.This routine blood test measures the levels of different components in the blood, including red blood cells, white blood cells, haemoglobin, and platelets. This blood test can help detect several conditions that may lead to hair loss, including anaemia, which occurs when there is a deficiency in red blood cells or haemoglobin. Anaemia is a common cause of hair thinning, particularly in women with heavy menstrual cycles or low iron intake. This test helps diagnose conditions like anemia, which, when caused by iron deficiency, can lead to hair loss due to insufficient iron required for hair follicle growth and maintenance.

2. Iron and Ferritin Studies

Iron helps produce hemoglobin, which carries oxygen to hair follicles to support healthy growth. Low iron levels can slow hair growth and lead to thinning. Ferritin is a protein that stores iron in the body. Low ferritin levels suggest depleted iron reserves, which can weaken hair and cause shedding. Ferritin and iron studies, which measure the levels of iron in the blood, are often among the first tests ordered for women experiencing hair loss. Ferritin is a protein that stores iron in the body, and low ferritin levels can indicate an iron deficiency, even before anaemia develops. Low iron levels can impair the production of healthy hair, leading to loss. Iron and ferritin studies can help doctors diagnose conditions like telogen effluvium, a hair loss condition that can result from iron deficiency.

Read also: Oral Minoxidil Treatment

3. Thyroid Function Tests (TFTs)

The thyroid gland, located in the neck, plays a significant role in regulating hair growth. Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can lead to hair loss. Thyroid function tests (TFTs) measure levels of your body’s thyroid hormones to assess whether the thyroid gland is functioning properly. A TSH test helps evaluate thyroid function and determines if thyroid problems contribute to hair loss.

4. Sex Hormone Tests

Hormonal imbalances involving testosterone, estrogen, or dihydrotestosterone (DHT), are a common cause of hair loss, especially male pattern baldness (androgenic alopecia). Hormonal imbalances are a common cause of hair loss in women. An imbalance in hormones such as testosterone, dihydrotestosterone (DHT), oestrogen, and progesterone can disrupt the hair growth cycle, causing thinning hair or pattern hair loss. A sex hormone blood test typically measures different hormone levels, including:

Testosterone
Oestradiol
Androstenedione
Prolactin
FSH (follicular-stimulating hormone)
Luteinizing hormone

If you are a premenopausal woman, your hormonal activity varies with the point you are at in your menstrual cycle. That is why you have to carefully follow your doctor’s instructions regarding the day after your menstruation when some of these tests should be taken.

5. Vitamin Level Tests

Vitamin deficiencies, especially in vitamin D and B12, can lead to hair loss. Vitamin D is vital for overall health, and plays a crucial role in the hair growth cycle. Studies have shown that women with low levels of vitamin D are more likely to experience hair thinning or diffuse hair loss. Testing for vitamin D levels is a common part of the diagnostic process for women experiencing hair loss, especially for those who live in areas with limited sun exposure, such as the United Kingdom.A 2023 pilot study linked vitamin D deficiency to alopecia areata, a condition where the immune system destroys hair follicles, leading to hair loss. Deficiencies in essential nutrients like B12, zinc, biotin, and folate can also contribute to hair loss. Zinc, in particular, is involved in hair follicle health, and low levels can lead to hair shedding.

6. Blood Sugar (Glucose) Levels

Glucose tests help doctors detect blood sugar imbalances linked to diabetes. A 2019 study found a strong link between uncontrolled blood sugar levels in type 2 diabetes and severe central scalp hair loss, particularly in African American women. The blood sugar level is an important indicator of diabetes. In particular, type 2 diabetes may be linked with hair loss. One study found that type 2 diabetes was associated with an increased risk of severe hair loss on the central scalp in African-American women. If you are not aware of being diabetic (as it doesn’t always produce clear symptoms early on), this test may be crucial to your health outside of your hair, and scalp issues as well. It can give you a chance to get diagnosed, and treated as soon as possible.

7. Inflammatory Markers

Chronic inflammation can interfere with the hair growth cycle, leading to conditions like telogen effluvium and alopecia areata. Tests like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels detect inflammation in the body. ESR and C-reactive proteins (CRP) levels can indicate systemic inflammation. Alopecia areata hair loss is often caused by inflammatory processes, so this test can help determine whether your diffuse hair thinning is caused by one of its atypical, diffuse forms called alopecia incognita.

8. Antinuclear Antibody Test (ANA)

An antinuclear antibody (ANA) test helps identify autoimmune disorders like lupus, which can damage the scalp and lead to scarring hair loss. An autoimmune condition is where the body attacks its own healthy organs and cells by mistaking them for foreign bodies. For women suspected of having autoimmune conditions, like alopecia areata, autoimmune screening tests may be ordered. These tests typically include antinuclear antibodies (ANA) and other markers that can indicate the presence of autoimmune activity. ANA testing helps doctors identify certain types of hair loss, especially if an autoimmune condition might be causing it.

9. Venereal Disease Test

Syphilis, a sexually transmitted infection (STIs), can cause hair loss. This often appears as patchy bald spots known as “moth-eaten alopecia.” A venereal disease test is specific for identifying infections like syphilis.

10. Cortisol Levels Test

Chronic stress can cause hair loss conditions like telogen effluvium, in which hair falls out more than usual because the hair follicles enter into a resting phase and stop growing prematurely. A cortisol test measures the levels of the stress hormone cortisol in your blood.

11. Zinc Levels

Zinc, in particular, is involved in hair follicle health, and low levels can lead to hair shedding.

Read also: Anatomy of Eyebrow Muscles

Additional Diagnostic Tests

In addition to blood tests, doctors may use other tests to diagnose hair loss, including:

Scalp biopsy: During a scalp biopsy, a small sample of scalp skin is taken and examined under a microscope to identify the cause of hair loss.
Pull or tug test: A doctor gently pulls hair strands to check how much hair is shedding. Losing 50 to 100 hairs per day is considered normal. During a pull test, a dermatologist grasps small sections of hair, about 40 strands, from different parts of the scalp and gently tugs. If six or more strands fall out, you have what’s known as active hair loss. During a tug test, the doctor grasps a section of hair and holds it with two hands, one near the root and one near the tip, then tugs to see if any of the strands break in the middle. This test gives the dermatologist information about the brittleness or fragility of your hair strands.
Medical history: A review of dietary habits, hair care routines, family history, and overall health can help identify possible causes of hair loss.
Physical exam: A doctor examines the scalp and hair to check the pattern of hair loss and look for signs of infection or other skin conditions. A dermatologist examines your scalp to check for inflammation, redness, sores, or scarring. The doctor looks closely at your hair to determine how much is being lost, the pattern of the hair loss, and whether there is hair breakage.
Card test: This involves dragging a small card against the hair to differentiate the newly growing hairs from the broken hairs. A dermatologist uses a card test to examine the health of hair shafts and to evaluate the number of new hair strands that are growing. The procedure is simple: The dermatologist creates a part in the hair and holds a small rectangular card covered in felt against a section of the scalp. The color of the felt should contrast with the color of the hair. New hair strands, even very small or broken ones, in this area are visible against the felt card and can be counted and examined.
Trichometric analysis: This test uses a digital tool to measure hair density, growth rate, and thickness, helping assess overall hair health and condition. In certain instances, dermatologists at NYU Langone use trichometric analysis, a sophisticated computerized measurement tool, to analyze characteristics of the scalp and hair. Our doctors use a digital assessment system called Folliscope® which consists of a small handheld device containing a high definition, microscopic camera. Doctors use this camera to take pictures of the scalp and hair, and the images are displayed on a computer monitor. The Folliscope® can magnify these images by up to 100 times, giving doctors a detailed look at hair, hair follicles, and the scalp.

Treating Hair Loss in Women

Treatment for hair loss depends on the cause. It may include:

Reducing your stress, like talking with a mental health professional.
Not using hair products (like chemical treatments) that damage your hair.
Taking vitamins or supplements for a vitamin deficiency.
Changing your hairstyling routine to avoid damaging your hair follicles.
Taking medications.
Managing any underlying health conditions.

In addition, a healthcare provider might recommend forms of light therapy like using the HairMax Lasercomb®. FDA to treat FPHL. Another FDA-approved laser product is the Theradome LH80 PRO® helmet and low-light laser helmets and caps.

If you have hair loss due to stress or hormone changes like pregnancy, you may not need treatment. The hair loss will stop after a period of time.

Other forms of hair loss treatment may include:

Microneedling of the scalp with and without the application of minoxidil.
Injections of protein-rich plasma (PRP) to encourage hair growth.
Hair transplant surgery. During hair transplant, tiny plugs of hair are removed from areas where hair is thicker, and placed (transplanted) in areas that are balding. Minor scarring may occur where hair is removed. There is a slight risk of skin infection. You will likely need many transplants, which can be expensive. However, the results can be excellent and permanent.

It’s important to talk to your healthcare provider before starting any form of treatment for hair loss. Some types of treatment aren’t safe to use if you’re pregnant, planning on becoming pregnant or going through menopause.

Medications for Hair Loss

A healthcare provider might recommend using minoxidil (Rogaine®). This is approved for treating FPHL. You can purchase the 2% or 5% solution over the counter (OTC). However, you have to follow directions exactly and use the product indefinitely. Don’t use this product if you’re pregnant, if you plan to get pregnant or if you’re breastfeeding.

Other medications that treat hair loss in women may include:

Spironolactone and other anti-androgens.
Finasteride and other alpha-reductase enzyme inhibitors.
Estrogens.
Prostaglandin analogs.
Steroids.
Ketoconazole shampoo.

Side Effects of Minoxidil

Minoxidil may irritate your scalp and cause dryness, scaling, itching and/or redness. See your dermatologist if this happens. With minoxidil, you might also see hair growing in places other than your scalp (cheeks and forehead, for example). Wash your face after you apply minoxidil and make sure you avoid other areas when you apply it.

Lifestyle and Home Remedies

You might want to try various hair care methods to find one that makes you feel better about how you look. For example, use styling products that add volume, color your hair, choose a hairstyle that makes a widening part less noticeable. Use wigs or extensions, or shave your head. Talk with a hair stylist for ideas.