Blood Tests for Hair Loss: What They Reveal and Why They Matter

If you ever notice you’re losing your hair, the best step to take is to book an appointment with a healthcare professional. That’s because, some of the time, sudden hair loss is caused by a medical condition, many of which can be identified by a blood test.

In this guide, learn all you need to know about blood tests for hair loss, including what they reveal and why they are so important.

Types of Blood Tests and What They Reveal

There are several different types of blood tests that doctors may use when investigating the cause of your hair loss. Here’s what each one looks into and why they matter.

Iron Levels

Checking iron levels is a particularly important type of blood test for female hair loss, as low iron levels are very common in women, with around 33.7% of women aged 15-49 experiencing anaemia in 2021 (compared to 11.3% of men). [1]

Blood tests for iron levels typically focus specifically on low ferritin levels. If you have low iron levels, you can usually treat them effectively with supplementation and dietary changes (although, if there’s an underlying reason behind your low iron levels, your doctor will also investigate that).

Thyroid Function

A blood test can measure your thyroid function, which assesses how well your thyroid gland is functioning. This is a useful blood test for people experiencing hair loss, as an overactive thyroid (hyperthyroidism) and an underactive thyroid (hypothyroidism), both autoimmune conditions, can contribute to this.

There are different types of thyroid tests; it’s best to get one that measures all of the following:

• TSH (Thyroid Stimulating Hormone)
• T4 (Thyroxine)
• T3 (Triiodothyronine)

Vitamin B12 Levels

Vitamin B12 is essential for healthy hair growth, as it boosts red blood cell production. When it’s at healthy levels, these blood cells carry all the essential nutrients around the body, including to the hair follicles. A vitamin B12 blood test will measure how much B12 is in your bloodstream, and the results can be very enlightening.

Vitamin D Levels

Another contributor to hair loss is a vitamin D deficiency, which is essential for healthy hair follicles and the production of keratin, which is the protein that your hairs are made of. If your vitamin D levels are not high enough, you may notice hair thinning or loss. A vitamin D blood test will show you whether this deficiency is the root cause of the problem.

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Hormone Levels

Understanding your hormone levels and whether you have a hormonal imbalance can be extremely useful when diagnosing hair loss conditions. That’s because certain sex hormones can contribute to hair loss in both men and women. For example, the presence of testosterone in women may cause hair loss, as well as other symptoms such as acne, excessive hair growth, and irregular periods. [2]

C-Reactive Protein

A C-reactive protein test measures how much C-reactive protein is in your blood. Excessive protein intake can indicate inflammation, which may contribute to hair loss. Plus, knowing that inflammation is present in the body can lead to a diagnosis of a chronic disease or infection.

Erythrocyte Sedimentation Rate

Another blood test that indicates inflammation in the body is the Erythrocyte Sedimentation Rate blood test. Again, this blood test can show inflammation that may be contributing to hair loss.

Blood Sugar Levels

A blood test can also be used to investigate your blood sugar levels. Healthy blood sugar levels change throughout the day and depend on when you last ate; for example, they should sit at around 4.0 to 5.4 mmol/L when fasting and reach up to 7.8 mmol/L two hours after eating. [3]

The reason for examining blood sugar levels is to determine whether a person has diabetes. High blood sugar levels characterise type 2 diabetes and can lead to hair loss (along with an array of other symptoms, such as thirstiness, blurred vision, and unexplained weight loss).

 

A Complete Blood Count

A good hair loss blood test looks into nearly everything, and that’s what a complete blood count does. A complete blood count will provide crucial information about the various types of blood cells in your blood, including platelets, white blood cells, and red blood cells. This can pave the way for a better, more accurate diagnosis based on any abnormal cell counts.

Why Blood Tests for Hair Loss Matter

Blood tests for hair loss are important because they help investigate the root cause of hair loss. It’s usually the first step for doctors, as it involves ruling out conditions that contribute to hair loss, such as low iron levels or thyroid function problems.

A blood test may simply show you exactly what’s leading to hair loss. Alternatively, it may rule out several conditions, allowing doctors to reach other conclusions, such as alopecia areata or hereditary hair loss. It means you’ll be able to seek the right hair loss treatment for you.

Additionally, experiencing sudden hair loss can be a sign of a more serious condition. By getting a blood test, you may receive an important diagnosis sooner, leading to better health outcomes.

Should You Get a Blood Test?

Have you experienced hair loss and are wondering if a blood test is a good option? Typically, it is the best next step in the investigation.

No matter what type of hair loss you are experiencing, whether you are noticing new bald spots, diffuse thinning, or frequent breakage, it helps to get a blood test.

Doing so is very easy and shouldn’t be painful. You simply need to schedule an appointment with your GP and explain why you would like to undergo the blood test. The process itself involves a healthcare professional locating the correct vein in your arm, applying a tight band (in some cases), wiping the area with an antiseptic wipe, and then drawing blood using a needle and collection tube or syringe.

It’s a very quick process, and the results you receive can lead to life-changing treatments, perhaps concerning both your hair and your overall health.

Types of Alopecia Blood Tests Can Help Diagnose

These are the types of hair loss conditions a blood test can help diagnose.

• Telogen Effluvium: Telogen effluvium is a very specific type of hair loss caused by psychological or physical stress. For example, surgery or an intense illness can cause it. It leads to fast hair loss that is typically temporary and resolves on its own in a matter of months. While a blood test cannot directly detect telogen effluvium, it can indicate underlying health conditions linked to this type of hair loss, such as iron deficiency or thyroid issues.
• Alopecia Areata: Alopecia areata is a type of hair loss in which your autoimmune system attacks the hair follicles. A blood test cannot directly diagnose alopecia areata, but it can help rule out other conditions and investigate autoimmune conditions that may be contributing to it.
• Thyroid Hair Loss: A blood test can help determine whether the thyroid is overactive or underactive, which can cause diffuse hair loss.
• Nutrient-Deficiency Hair Loss: Any hair loss caused by a nutritional deficiency, whether that’s vitamin B12 or vitamin D, can be detected by a blood test.

What About Male or Female Pattern Hair Loss?

Blood tests are not the best diagnostic tool for female and male pattern baldness (androgenetic alopecia). That is a hereditary hair loss that is determined by genetics rather than vitamin or hormonal levels. The only way a blood test is useful in this situation is to rule out other potential causes of hair loss.

Common signs of androgenetic alopecia in men include:

• A Receding Hairline
• Overall Thinning
• A Thinning Crown
• A Family History of Hair Loss
• Slow Onset of Hair Loss

Signs of androgenetic alopecia in women include:

• Gradual Thinning
• Thinning at the Crown
• A Widening Parting
• Shrunken Hair Follicles

Diagnosing androgenetic alopecia often includes a mixture of tests (often including blood tests to rule out other causes of hair loss). A healthcare professional may inspect your scalp and perform a hair pull test.

It can be hard to accept genetic hair loss, but it’s not something you have to live with. There are several good hair restoration options out there, including medications like minoxidil and finasteride, as well as more permanent treatments like a hair transplant.

Hair Loss Blood Tests: In Summary

Blood tests for hair loss are useful, as they help diagnose problems that may be causing the hair to fall out. Keep in mind there are several different types of blood tests, and, most of the time, a single blood test at your GP will not show everything. You may need several blood tests for an overall view of your health, including one that looks into vitamin levels, thyroid function, and iron levels.

Are you experiencing hair loss and are looking for a permanent solution? The team here at Harley Street Hair Clinic can help you. If you want to learn more about what we do for our clients, head over to our patients gallery – the results speak for themselves.

Sources:

1. https://www.healthdata.org/news-events/insights-blog/global-health-insights/podcast-anemia-remains-stubbornly-common-women-and
2. https://www.medicalnewstoday.com/articles/321292#:~:text=What%20happens%20if%20testosterone%20is,a%20larger%20than%20average%20clitoris
3. https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/tests/blood-sugar