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Why Do White Blood Cells Attack Hair Follicles? Auto-Immune Conditions And Hair Loss

Medically reviewed by
Dr Mir Malkani — Written by — Updated on December 29, 2025

There are many causes of hair loss. Although genetics is the biggest cause of hair loss, it can also be triggered by illness and disease. This typically stems from autoimmune diseases, which can cause white blood cells to attack your hair follicles, preventing them from producing hair.

In the UK, it’s estimated that at least 4 million people are living with at least 1 autoimmune disease [1]. Here’s a look at autoimmune diseases, some of which can cause hair loss.

Table of Contents

What is an autoimmune disease?
What role do white blood cells play in autoimmune disease-related hair loss?
Types of autoimmune diseases that cause hair loss
Why do white blood cells attack hair follicles?
Is your hair loss related to an auto-immune disease?

What is an autoimmune disease?

The body is protected by the immune system, a complicated set of organs and cells which include the bone marrow, spleen, thymus, white blood cells and lymph nodes.

The various organs and parts of the body which make up the immune system are specifically designed to be able to recognise and deal with invaders like viruses, bacteria, fungi, and other pathogens. Normally, they isolate and fight any foreign bodies voraciously.

However, when an autoimmune disease occurs, the body can’t tell the difference between its own healthy cells and foreign invaders. This breakdown in the immune system can result in a wide range of symptoms, including hair loss.

What role do white blood cells play in autoimmune disease-related hair loss?

White blood cells (also known as leukocytes) are responsible for locating and fighting infection in your body. There are 5 types of white blood cells, each of which has a different role to play in helping your body fight disease. They are all triggered to respond when the body detects foreign bodies like bacteria or germs by surrounding and suppressing the invading cells to defend your body from illness.

When a person has an autoimmune condition, white blood cells suppress healthy cells. This can be in specific organs, such as the skin (in psoriasis) or pancreas (in type 1 diabetes [2]). Certain conditions — such as alopecia areata — cause white blood cells to attack healthy hair follicles.

Let’s take a look at some of the autoimmune disorders you could be affected by.

Types of autoimmune diseases that cause hair loss

Alopecia Areata

Alopecia areata is an autoimmune disease that specifically relates to hair loss. It’s caused by the hair follicles being attacked by the immune system [3].

When the follicles are attacked by the white blood cells, it results in patchy hair loss due to the hair growth pattern in the follicle being directly interfered with. Despite this attack by the immune system, the hair follicles remain alive and have the potential to once again recover full functionality. Meaning that people with alopecia areata are fully able to regrow their hair again with proper treatments.

Alopecia areata affects thousands of people in the UK. You may develop alopecia areata if you:

Are between the ages of 25-40 years old
Are of non-white ethnicity
Have a close relative who has alopecia areata
Suffer from asthma, hayfever, or allergies
Have Down’s syndrome
Have taken Nivolumab as a cancer treatment

Alopecia areata has many different forms. It may attack other parts of the body too.

Diffuse alopecia areata

Instead of patchy hair loss, this type of alopecia areata is characterised by widespread hair thinning across the entire scalp. This type of hair loss tends to occur over a longer period of time.

Alopecia barbae

When it affects the beard, the condition is known as alopecia barbae. Along with the typical patchiness seen on the hair on your head, the disease can also manifest in loss of facial hair, eyebrows and even eyelashes.

Ophiasis alopecia areata

In some cases, it can spread further. Ophiasis alopecia is characterised by a band of baldness across the back of the scalp.

Alopecia totalis

Alopecia totalis is a form of alopecia areata that results in total loss of scalp hair, causing complete baldness.

Alopecia universalis

Alopecia universalis results in complete hair loss everywhere on the body. This includes scalp and body hair.

Lupus

A type of autoimmune disease that doesn’t primarily affect the hair follicles, but lupus can still have a very profound effect on hair loss.

No one knows exactly what causes lupus, but it often occurs within families, leading scientists to speculate that genetics may play a part [4]. A specific trigger then seems to set the disease process off, with several problems arising right across the body.

Some of the symptoms lupus can cause include fatigue, painful joints, headache, lethargy, anaemia and clotting, along with hair loss.

Lupus is often dubbed the “great imitator” because the symptoms which arise are common and can be attributed to a number of different conditions.

Hashimoto’s disease

Also referred to as chronic lymphocytic thyroiditis, Hashimoto’s disease is an autoimmune thyroid disease where the immune system cells attack the thyroid gland [5].

The thyroid gland is responsible for regulating a number of activities within the body and damage to it can cause widespread symptoms. Being attacked causes inflammation, which impairs its ability to function, causing an underactive thyroid gland.

The disease has a slow progression initially producing few if any, symptoms but as the level of thyroid hormones in the blood starts to drop, problems start to become noticeable. Sluggishness and fatigue are the first symptoms typically noticed, and then sensitivity to the cold, unexplained weight gain, a puffy face, muscle aches and a hoarse voice occur, in addition to hair loss.

Why do white blood cells attack hair follicles?

Doctors still don’t know definitively what causes white blood cells to attack hair follicles, but there are many theories:

Genetics — conditions like Lupus often run in families, so you may be genetically predisposed to certain autoimmune disorders.
Accidental targeting — sometimes healthy cells are caught up in an immune response to real infections, causing damage to peripheral cells [6].
Diet — it’s been suggested that Western diets, which are high in fat and sugar, may be responsible for some autoimmune diseases [7].
Hygiene hypothesis — lack of exposure to germs thanks to improved hygiene and vaccines has led to more autoimmune conditions and allergies [8].

None of these have yet been definitely proven, and since there are more than 80 autoimmune conditions, it’s likely that there are a range of contributing factors. Nonetheless, if you’re worried you may be suffering from an autoimmune disorder, it’s important to see a doctor so they can help diagnose your condition and help you manage your symptoms.

Is your hair loss related to an auto-immune disease?

Many auto-immune diseases have symptoms which can mimic other conditions, so it’s important not to panic if you suffer from hair loss. You could be suffering from stress-induced hair loss or another type of alopecia.

Nevertheless, if you experience hair loss, you should be seen by a professional, to rule out any underlying medical cause as well as offer a potential treatment that’s right for you.

Book a free consultation with a trichologist for an expert medical examination to establish the cause of your hair loss.