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Blood Tests for Hair Loss: Diagnosing Female Hair Thinning
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on July 31, 2024

Determining the cause of women’s hair thinning can be difficult and trichologists may require hair loss blood tests to provide an accurate diagnosis. While hair loss is more common in men than in women, it still affects a significant part of the female population.

Research shows that 52% of the postmenopausal population have female pattern baldness [1]. Stress, health conditions, diet, hair care, and other factors can also cause hair loss in younger women.

Unlike male pattern baldness, the female variety is more diffuse and easier to mistake for other conditions, such as diffuse alopecia areata or telogen effluvium. Systemic conditions, such as thyroid hair loss or vitamin deficiencies can also cause hair thinning.

Understanding the reason your hair is falling out is crucial to determining the appropriate course of treatment. And getting the right blood tests can help you uncover the causes behind your hair loss or at least rule out conditions you do not have. This article will help you discover:

  • Why hair loss blood tests are needed, particularly for women
  • Which blood tests you may need and what they can tell you about your hair
  • Where to get hair loss blood tests.
  • What are some of the best treatments for different conditions your blood tests may reveal
Table of Contents

What hair loss blood tests do women need and why?

Your blood can provide an abundance of information about the state of your health. But it can also tell you more about what conditions could be affecting your scalp and hair. Here are some of the most frequently ordered hair loss blood tests, which can provide hair doctors with the information they need to establish a confident diagnosis: 

Thyroid levels

Thyroid dysfunction and hair loss have been long linked, as it can affect your hair growth cycle, reduce the amount of oxygen and nutrients that reach your hair follicles, and give you dry, brittle hair.  Hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can both cause hair loss if left untreated.

Your thyroid produces hormones known as thyroid stimulating hormone (TSH), free triiodothyronine (FT3) , and free thyroxine (FT4).  Blood tests can measure how much of each hormone you’re producing, determining whether you have an overactive or underactive thyroid. 

Sex hormones

Sex hormone levels play a big part in maintaining hair growth in women as well as men. Women also produce certain quantities of male hormones, such as testosterone, which is metabolised into different androgen called Dihydrotestosterone (DHT). DHT binds to androgen receptors in the hair follicles, causing them to shrink, and stop producing hair.

Normally, female hormones (e.g. oestrogens) balance out male ones. However, if the balance between male and female hormones is offset (as can happen at puberty, during perimenopause or after menopause), blood levels of DHT can increase, leading to female pattern baldness. 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. Otherwise, the results may be misleading. 

Hormone levels can also indicate the presence of conditions like polycystic ovary syndrome, which may also cause hair loss.

Iron and ferritin levels

Some studies have linked iron deficiency anaemia and hair loss. There may also be a connection between iron deficiency and hair texture.

Studies have shown that levels of serum ferritin (the blood protein that contains iron) are lower in women with female pattern hair loss than those with healthy hair [2]. Lack of iron may also contribute to the development of alopecia areata [3]. So testing your iron and ferritin levels can give an insight into which type of hair loss you have.

Complete blood count

CBC or full blood count measures individual components of your blood, including red blood cells, white blood cells, and platelets. This test can reveal signs of infection or inflammation in your body, which might also affect your hair.

It can also be a first step in detecting various systemic illnesses which may be involved in your hair thinning. A complete blood count alone can often be insufficient to diagnose your alopecia, but it can paint a clearer picture when used alongside other diagnostic tests. 

Vitamin D levels

Vitamin D deficiency may cause hair loss, as it has been linked with autoimmunity, so it may worsen or cause autoimmune hair loss conditions like alopecia areata [4]. Research also suggests this deficiency can play a part in the progression of female pattern hair loss [5].

Vitamin B levels

There are several different B vitamins, and having a clinical deficiency of any of them has been linked with hair loss. That is because the body needs them to produce healthy strands.  The B vitamin deficiency most frequently connected with hair shedding include:

Hair loss blood tests will check your vitamin B levels to test for deficiency. If the results come back positive, it is a good idea to see your GP and try to figure out its cause. That is because people in developed countries rarely develop deficiencies from low dietary intake. You may have issues absorbing these vitamins due to conditions such as pernicious anaemia, gastrointestinal disorders or autoimmune diseases. 

Blood sugar

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 [7].

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. If you discover you are prediabetic, it is a good opportunity to make the necessary lifestyle changes to prevent the onset of this disease.

ESR and C-reactive protein

Erythrocyte sedimentation rate (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.  Moreover, certain types of scarring alopecia are also often associated with inflammation around the hair follicles. 

Why are blood tests needed to diagnose women’s hair loss?

Some of the most common conditions that cause hair loss in women can present with very similar symptoms. The main one is diffuse hair thinning – where your strands fall off from all over your scalp, rather than following a distinct and easy-to-recognise pattern, as it happens with male pattern baldness. They can be even trickier to tell apart in early phases when treatment is most effective. Sometimes, trichologists can glean the reason your hair is falling out, if the presentation is more typical. 

What types of alopecia may require hair loss blood tests?

Here are some examples of conditions that may present simply with diffuse hair loss, but may also have more distinct symptoms:

Woman with female pattern hair loss
Woman with female pattern hair loss [8]

Female pattern hair loss

This is the female version of androgenetic alopecia. It is less common than male pattern baldness, but it still affects about half of women over the age of 50 to some extent. 

Causes: a combination of age, hormones, and genetics

Most recognisable symptoms: a widening of the midline parting, a Christmas tree pattern around your parting, diffuse hair loss.

Woman with telogen effluvium
Woman with telogen effluvium [9]

Telogen effluvium

This is normally a temporary condition which occurs after very physically or psychologically stressful events. Telogen effluvium usually resolves itself in about 4 months once the triggering event is over.  

Causes: severe psychological stress, illness, surgery, or other major disruptions to your physical or psychological wellbeing.

Most recognisable symptoms: diffuse hair loss, in some cases, a burning sensation on the scalp

Woman with alopecia areata
Woman with alopecia areata [8]

Alopecia areata

This condition affects 2% of the world’s population and can take multiple forms. The most common involves patchy hair loss.

Causes: Autoimmune (your white blood cells are attacking your hair follicles)

Most recognisable symptoms: typically, round, smooth, patchy bald spots, black or yellow dots on the scalp, and broken hairs shaped like exclamation marks. However, in some cases it can manifest with diffuse hair loss (alopecia areata incognita), with large bald swathes on your scalp or with full baldness on your scalp and face (alopecia totalis), or all over your body (alopecia universalis). 

Woman with thyroid hair loss
Woman with thyroid hair loss [10]

Thyroid hair loss

If your thyroid is either underactive or overactive, this can affect your hair, leading to thinning and changes in your hair appearance and texture. 

Causes: hyperthyroidism or hypothyroidism

Most recognisable symptoms: diffuse hair loss, sometimes eyebrow hair loss, changes in hair texture (it can become coarser or finer, and more brittle than it used to be), premature greying.

Nutrient deficiency-induced hair loss

Nutrients such as vitamins, minerals and protein are essential to growing full, healthy hair. Due to a restrictive diet or to health conditions that interfere with nutrient absorption, your body may not get enough of these nutrients, leading to a clinical deficiency. 

Causes: insufficient intake or poor absorption of nutrients, such as vitamins B, C, D, E, protein or minerals such as iron, zinc, magnesium, etc.

Most recognisable symptoms: diffuse hair thinning

Lupus-induced hair loss
Woman with diffuse hair loss due to acute lupus erythematosus [11]

Systemic illness-induced hair loss

Causes: This depends on each condition, but many (e.g. Diabetes, lupus) are linked with diffuse hair loss.

Most recognisable symptoms: Since these hair loss types look similar, visual tests aren’t always the best way to diagnose them. The Ludwig Scale, for example, can only measure the extent of hair loss, rather than the type. Blood tests for hair loss in females are the fastest, most reliable way to determine the cause of hair loss in women.

Man wondering about hair loss blood tests

Can men also get hair loss blood tests?

Yes, men can also benefit from blood tests for hair loss, especially when they’re not showing typical signs of male pattern baldness. Most types of alopecia that affect women can also affect men, even if more infrequently.

So if a trichologist suspects that their male patients may be affected by a nutritional deficiency or systemic illness that could be causing their hair thinning, they are likely to order such tests and remove all doubt.  

Where should you get hair loss blood tests done?

In some cases, your GP will perform the necessary blood tests for you. Hair loss blood tests carried out through your GP are usually free. However, a GP may not read the results in the same way as a trichologist. What’s considered normal for your general health may still be damaging your hair. 

You can also get blood tests done at a private hair clinic. Our trichology team can diagnose your hair loss condition based on your hair loss blood tests, regardless of your age, sex, or gender. We’ll then use this information to create a personalised female hair loss treatment plan for you.

What other hair loss tests can help diagnose my alopecia?

While blood tests can give you much-needed information, there are also many other trichology diagnosis tests you may be recommended. Here are some of the most common [12]:

Dermoscopy picture of female pattern baldness
Dermoscopy picture of female pattern baldness [12]

A dermoscopy (or video dermoscopy)

Dermoscopies and videodermoscopies allow the trichologist to get a magnified (20x-70x), high-resolution view of the scalp, strands and hair roots. This allows them to visualise symptoms such as scalp inflammation, black dots, empty follicles or short, broken hairs on the scalp. They can also observe skin hyperpigmentation, signs of infection, rashes or scarring which may be difficult to observe with the naked eye. 

A trichogram being performed
A trichogram being performed [12]

A trichogram (hair pluck test)

The trichogram involves fixing a tuft of hair from a client who hasn’t used shampoo for 5 days with clips. Then, the doctor uses a hemostat covered in rubber to pluck, twist and lift 60-80 of these hairs until they come out. These strands are then cut starting 1 cm above the root.

The roots are kept and taped side by side on a slide. The bulbs of the hairs that were in a growing phase have a darker colour and are delta-shaped, while those in a resting/shedding phase are lighter coloured and club-shaped. This allows the doctor to determine the proportion of growing versus shedding hair

Doctor performing a hair pull test
Doctor performing a hair pull test [12]

A hair pull test

During a hair pull test, about 20-60 hairs are grasped firmly between the trichologist’s fingers and gently tugged at. If more than 10% of them come off during this manoeuvre, it means the test is positive and you are experiencing active hair shedding. 

Doctor performing a contrasting felt test
Doctor performing a contrasting felt test [12]

A contrasting felt test (card test)

This test involves using an index card which has black fabric (often felt) on one side and white fabric on the other. The doctor parts your hair and runs the index card along your scalp. This makes fine, short hairs (vellus hairs) or broken ones easily visible, as they are lifted up by the card. The contrasting felt test is often used to spot hair miniaturisation in androgenetic alopecia.

Androgenetic alopecia revealed by a scalp biopsy
Androgenetic alopecia revealed by a scalp biopsy [12]

A scalp biopsy

A biopsy involves taking small skin samples from the area that needs inspection (in this case, the problem areas on the scalp) and analysing them under a microscope. This can reveal the inner structure of the skin, and hair follicles.

Normally, an approximately 12.5 mm sample is collected, under local anaesthesia. Biopsies can reveal an abundance of information about scalp and hair conditions, and are useful in diagnosing most common types of hair loss, such as androgenetic alopecia, telogen effluvium or alopecia areata. 

Woman getting hair loss blood test results

What treatments can I get after my hair loss blood test results?

Once you have received your results, your hair doctor will either order more tests as needed, or formulate a diagnosis. If the cause of your hair loss has been determined, you are ready to start treatment. Depending on your condition, the trichologist might recommend:

Woman using hair loss medication

Hair loss medication

Drug treatments such as Minoxidil can help with many kinds of hair loss, from female pattern baldness to chronic telogen effluvium, advanced traction alopecia and alopecia areata. It can even help stimulate hair growth in certain types of systemic or nutrient deficiency-induced alopecia, provided that you are also treating the underlying cause. 

Steroid creams or steroid injections can be used to treat inflammatory hair loss, such as alopecia areata or frontal fibrosing alopecia. They can help reduce the inflammation, giving the hair follicles a chance to heal. 

If you are experiencing androgenetic alopecia as a postmenopausal woman, you might even be prescribed Finasteride. While premenopausal women can’t use Finasteride due to concerns regarding foetal malformations or hormonal imbalances, it can sometimes be recommended to women who have already undergone menopause.  

Woman using hair growth therapies

Hair growth therapies

There are a variety of therapies which can support the process of curbing your hair loss and achieving regrowth, usually alongside other treatments, such as medications. The most effective, scientifically proven such therapies are PRP hair treatment, red light therapy for hair growth and derma rolling for hair growth.

They each function through different mechanisms and can be used together in many conditions for enhanced results. While the evidence is less compelling, many women also try scalp massages for hair growth, which also work as a good method to relieve stress.  

Doctor suggesting lifestyle changes

Lifestyle changes

If your blood tests reveal a nutrient deficiency and you have been on a restrictive diet, the doctor may recommend you eat more balanced meals, to ensure your daily recommended dose. You may also be recommended supplementation, but it is good to know that for many nutrients (e.g. B vitamins), there is no evidence that it will make your hair regrow. 

 If you are experiencing a systemic disorder, you may need to get treatment for it or to manage it better if you already had treatment (e.g. type 2 diabetes). If your hair loss is medication-induced, you may need to ask your doctor whether there are any alternatives to the respective medication which do not affect your hair. 

Moreover, if you are a smoker experiencing female pattern hair loss or alopecia areata, you may be asked to quit. That is because smoking can cause hair loss, as nicotine can trigger or worsen both of these conditions. 

Female hair transplant at the Wimpole Clinic
Before and after a female hair transplant performed at the Wimpole Clinic

A hair transplant

If you are experiencing female pattern hair loss, you may be a good candidate for a hair transplant. In the past years, female hair transplants have been soaring in popularity. That is because they are the closest you can get to a cure for baldness with today’s technology. 

The procedure is safe and simple and takes place under local anaesthesia. So you are awake the entire time but cannot feel any pain. The surgeon harvests some healthy hair follicles from the back of your head and implants them in your thinning spots, such as your crown. And if you opt for an FUE procedure, you will have no visible scar, so you can get a hair transplant without anyone knowing

The best part about surgical hair restoration is that a hair transplant is permanent. Since the hair grafts are obtained from parts of your head not affected by DHT, your pattern baldness will not make them fall out as well. So you can enjoy your youthful appearance 10 years after your hair transplant and more. 

Do you need a diagnosis for your hair loss?

If you are concerned about your hair loss and interested in getting an accurate diagnosis, you’ve come to the right place. Our top-tier trichologists at the Wimpole Clinic are always available to examine you and recommend the most appropriate tests to get to the root of your alopecia.

Once they have made their diagnosis, they will recommend the best hair loss treatment for women, tailored to your specific condition. They will also tell you everything you need to know about the best haircare routine for thinning hair.

So don’t wait until your hair loss advances to the point of no return. Book a consultation today at your most convenient clinic location and take the first step towards reclaiming your healthy, beautiful locks.

Blood Tests for Hair Loss: Diagnosing Female Hair Thinning, Wimpole Clinic

Frequently asked questions

Find out even more about hair loss blood tests by reading the answers to some of the most common questions on this matter:

You can get some of the blood tests you need to assess your hair loss on the NHS, as long as your GP or specialist orders them for health purposes. Your CBC or blood sugar test, for example, are routine tests that everyone should be getting at least once a year.

If your doctor already suspects you may have a thyroid disorder or a hormonal imbalance, you may be able to get those tests compensated as well, as they are necessary for your health. However, it may be more difficult to get more specific tests, such as blood DHT levels, compensated. That is because in most cases, hair loss is considered a cosmetic issue and you can’t get tests or treatment on the NHS for it.

Your GP should be able to accurately interpret most of these blood tests in terms of your general health condition. For example, they will be able to tell you if you have a vitamin deficiency, anaemia, a hormonal imbalance or diabetes.

However, it takes a trichologist to tell you the implications of your test results on your hair loss and the correct treatment to curb your alopecia and obtain hair regrowth.   

While there are some home testing kits available for commercial use, they may not provide as accurate results as getting a professional blood test read by a laboratory. If the results are inaccurate, they can be misleading and prevent you from getting the treatment you need in a timely fashion.  

No, this article presents some of the most common hair loss blood tests your trichologist may order. However, depending on your specific condition, they may only require some of these or ask for other, more specific ones that are not on this list.

Your hair doctor is the best person to determine which blood tests you need so they can provide you with an accurate diagnosis for your hair loss.

Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on July 31, 2024
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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