The Importance of Blood Test for Hair Loss (Updated)



Hair loss is an enormous part of our lives. While hair loss might be because of heredity reason 90% for men, this condition is a bit different for women. They might face many different reasons. To have a successful treatment, a correct diagnosis is needed.

There are many ways to diagnosis hair loss such as light microscopy, scalp biopsy, and pull tests. A hair blood test is one of them.

A hair blood test to diagnose hair loss could include many subtests to figure out the situation better. The series of blood test can be listed like this for you:

  • Thyroid stimulating hormone (T3, T4, TSH)
  • Serum iron and serum ferritin levels
  • Antinuclear Antibodies (ANA)
  • Complete blood count (CBC)
  • Total iron binding capacity (TIBC)


Thyroid Stimulating Hormone (T3, T4, TSH)


This test is also known as thyrotropin test to measure the level of TSH stimulating thyroid hormone. The thyroid is quite important in terms of regulating hormonal balance in the body and regulating the way your body uses energy.

Also, when you gain weight suddenly, or when you lose weight all of a sudden, the first thing your doctor does probably will be to check the thyroid hormone level. It is because it has an important role in regulating your weight. Bot only your weight, but also the body temperature, muscle strength, and even your mood have affected by this hormone.

When it comes to the hair loss problem, it is about how your thyroids work. For instance, while your thyroid levels in your body are low, the pituitary gland makes more TSH, your thyroid levels are high, the pituitary gland makes less TSH. That is why how well your thyroid works is critical.



After taking your blood test results, you might encounter two main types of problems: hypothyroidism that is when the high TSH levels place and does not make enough thyroid hormones, hyperthyroidism which is the low TSH levels resulting in your thyroid is making too much of the hormones.

Both might be a reason for hair loss for you. To take prevention, here are the symptoms of hyperthyroidism and hypothyroidism.

Symptoms of overactive thyroid problems; hyperthyroidism:

  • Anxiety
  • Hair loss
  • Weight loss
  • Puffiness
  • Tremors in the hands
  • Increased heart rate
  • Difficulty sleeping
  • Bulging of the eyes


Symptoms of underactive thyroid; hypothyroidism:

  • Weight gain
  • Hair loss
  • Tiredness
  • Low tolerance for cold temperatures
  • Irregular menstrual periods
  • Constipation

The optimum levels for (T3, T4, TSH)

TSH(Thyroid Stimulating Hormone): optimum level: .3 to 3.0 ml U/L

(for those who are on thyroid medication already, the optimum level is between .5 and 2.0 ml U/L)

Total T3: optimal level: 100 to 200 ng/dL

Free T3: optimum level: 2.3 to 4.2

Total T4 (Total Thyroxin): optimum level: 4.5 to 12.5 mcg/dL

Free T4 (Free Thyroxin): optimum level: .7 to 2.0



Serum Iron and Serum Ferritin Levels


The zinc and iron level has an important role in hair growth and hair loss, too. In fact, ferritin loss might cause hair loss problem for many. The connection with iron is here: when your body needs iron because of the low level of iron, it has to use ferritin from your hair follicles. Therefore, it resulted in hair loss problem and other illnesses.

What I can suggest you is to have a healthy diet with the high level of iron because if you get enough iron from foods or supplements, you will not have this problem with the adequate ferritin in the body.

Not only the lack of iron but also the low level of ferritin might be because of some other problems for your health. For example, it may be because of significant blood loss, pregnancy, celiac disease, and even hypothyroidism (low thyroid).

Because the ferritin level affects how the system of red blood cells works, it is better to realize it as soon as possible for your hair loss and hair growth.



Here are some symptoms of the low ferritin level:

  • dizziness
  • extreme fatigue
  • pounding in the ears
  • brittle nails
  • shortness of breath
  • headaches
  • difficulty concentrating
  • restless legs

Antinuclear Antibodies (ANA)


Antinuclear Antibodies (ANA) tests measures the amount and pattern of antibodies in your blood that works against your own body. In other words, it is necessary to measure the autoimmune reaction of your body.

Antibodies are proteins your immune system that your body needs to make you stronger when fighting off bacteria, viruses, and other germs.

When your body becomes weak in terms of this strength, it is possible to experience hair loss problems. That is why your blood test should include Antinuclear Antibodies when clicking on hair loss problems.



There are many symptoms related to autoimmune disease as well as hair loss. They can be listed as:

  • Tiredness
  • Recurring or persistent fever
  • Weakness
  • Joint and muscle pain
  • Light sensitivity
  • Numbness and tingling in your hands and your feet
  • Rash

If your ANA test is positive, you might need some more additional blood test. That means your doctor might then test you for ANAs that are specific to certain diseases. For example, Anti-centromere that diagnoses scleroderma and Anti-double-stranded DNA which diagnoses lupus can be requested.



Apart from that, the ENA panel helps your doctor see which autoimmune disease you have, and lastly, Anti-histone test helps to diagnose lupus that was caused by a medicine you took.


Complete Blood Count (CBC)


The components of complete blood count include mainly white blood cell count (WBC or leukocyte count), WBC differential count, red blood cell count, and platelet count.



The cells in the CBC (white blood cells, red blood cells, and platelets) with its unique functions is very essential to test for the immune system because it helps the body fight infections. Not only the amount but also the number of different component of the white blood cell is important since each plays a specific role in the immune system, just like red blood cells.

This test can be done as a part of an evaluation based on a patient’s symptoms including hair loss. According to your result, you should follow your doctor’s advice.

The optimum levels for CBC test:

RBC (Red Blood Count): normal levels: 4.2 to 5.4 mil cell/mcL

WBC (White Blood Count): normal levels: 4500 to 10000 cells/mcL

Hematocrit: normal levels: 36.1 to 44.3%

Hemoglobin: normal levels: 12.1 to 15.1 gm/dl

MCV: normal levels: 80 to 95 femtoliter

MCH: normal levels: 27 to 31 pg/cell

MCHC: normal levels: 32 to 36 gm/dL



Total Iron Binding Capacity (TIBC)


Total iron binding capacity helps to measure the ability of a protein called transferrin to carry iron in the blood. The reason why it is getting tested is to assess one’s body’s ability to transport iron in the blood. Therefore, it might help diagnose iron-deficiency or iron overload, which cause hair loss.

By taking a blood sample drawn from a vein in your arm, they can understand whether or not you have low hemoglobin and hematocrit on a complete blood count (CBC). In short, this test is necessary to understand if you may have too much iron (overload) or too little iron (deficiency) in the body.

The optimum levels for TIBC tests:

The optimum levels for TIBC tests:

Serum Iron: optimum level: 60 to 170 mcg/dl

Serum Ferritin: optimum level: 12 to 150 ng/ml

TIBC (Total Iron Binding Capacity): optimum level: 240 to 450 mcg/dl



Hair Blood Test for Men


It is generally rare for a doctor to ask for a hair blood test when it comes to men because is generally because of heredity problems. Apart from that, hair loss for men might be because of some autoimmune problems. They are causes like alopecia areata and lichen planopilaris.

If there is a need for a hair blood test, basic blood counts (CBC), thyroid (TSH), iron status (ferritin), ANA, B12, and ESR should be checked.


Hair Blood Test for Women


This condition is a bit different for a woman. There should be a blood test for sure to understand what is going on. In other words, blood tests are mandatory for a woman when it comes to hair loss issue.

The reason for this mandatory situation is about the fact that there are many reasons and diagnosing behind female hair loss. They can be thyroid (TSH), iron (ferritin), and basic blood counts (CBC). However, there are some additional tests depending on the age of the woman.



For instance, a test for DHEAS (hormones from the adrenal gland), androstenedione (hormones from the ovaries), and the free and total testosterone and sex hormone binding globulin (SHBG) is necessary when it comes to young ladies.

If the hair loss problem goes together with an irregular menstrual cycle, this time it will be needed to evaluate polycystic ovarian syndrome. They include other tests for LH, FSH, DHEAS, androstenedione, prolactin, estrogen, and 17 hydroxyprogesterone (17 OHP), as well as SHBG. It is also possible to check blood sugars for some doctors.

If the women have some dietary restrictions, now it is needed to have zinc levels checked. Also, the mineral level is important together with Vitamin D depending on the place the patient lives.


What to Know Before the Blood Test for Hair Loss?


When you go to the doctor because of the hair loss problem, there are some procedures your doctor will go through before the blood test. It would save you time to be prepared against this so that you will be ready for your doctor appointment.

The type of your hair and your lifestyle are quite important for your scalp conditions. Apart from that, the doctor should know about your medical history.

If you have blood test results in recent dates like 1-2 years old, it would be a good idea to bring the papers together with. In fact, your medical history as a previous condition may be contributing to your hair loss or scalp condition.



Not only your own medical history but also the situation of your family is important in terms of analyzing some genetic influences on your hair loss.

If you know well about your family history and family genetic diseases, I am sure your doctor will be happy and it will be easier for him or her to diagnosis. After that, your doctor can decide about which treatment you need and what to follow against your hair loss problem.



Although hair loss might be seen as a social problem related only the physical environment, the reality is that hair growth and loss is strongly associated with your diet and sleeping habits. For example, if you consume alcohol or smoke excessively, it is more possible to experience hair loss problems.

Apart from that, the tools you use when combing your hair and washing are important as it affects the features of your hair in time. That is why your doctor might have some questions about your way to care your hair.

Regardless of the result of the blood test, you should organize your daily diet in a good way so that your hair loss problems would be the temporary one. Your doctor might want you to have a healthy diet. That is why it is a good idea to make it your daily habit before visiting your doctor.

In other words, you should have a well-balanced diet to affect hair growth and condition in a good way possible. For instance, A lack of vitamins, iron, zinc, and folic acid will surely stunt hair growth.



When it comes to lifestyle, the first thing coming to our minds is stressful conditions. It is the most dominant thing as it might cause even trauma.

The reason why your doctor will ask you about your stress level nowadays before applying the blood test is to check your psychological condition. It is important because it might determine your hair loss being temporary or permanent accordingly.

In fact, the high-stress level is one of the most common causes of dramatic hair loss. What I suggest you are not to hesitate when telling your doctor about your stress condition. Otherwise, the doctor might diagnose wrongly, which will surely affect you negatively in the future.

Savaş Ateş

I'm a hair loss expert. The picture was taken 10 years ago :) I have been losing my hair. So I started to learn everything about hair loss and hair transplants. I contacted a lot of hair transplant doctors. We shared our experiences. I'm writing blog posts for people who have the potential of losing their hair. I give some tips about hair transplants and medical issues too.

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