Illnesses that can cause hair loss

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Alexandria Bachert 

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Alexandria Bachert 

last updated: Jul 27, 2020

6 min read

Genetics, stress, extreme weight loss, age; there are myriad reasons that can lead to hair loss. Some causes are within your control, while others develop as the inherent course of nature and father time.

Although alopecia is relatively common both in the United States and across the globe, multiple studies have shown that living with hair shedding, thinning, or baldness can have a psychosocial impact on both men and women. For women, in particular, evidence suggests that alopecia can cause emotional suffering and lead to personal and professional problems.

According to a clinical review of 34 studies on alopecia published over the last four decades, 40% of women with alopecia have experienced marital problems due to the condition, and about 63% reported problems with their career (Hunt, 2005).

Balding or thinning hair can be especially devastating for those who lose their hair due to illness. One consolation is that, when it comes to alopecia, knowledge is power. Understanding what type of hair loss you have and how exactly it relates to your other conditions allows you the opportunity to repair your existing follicles and prevent future damage.

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Illnesses linked to hair loss


Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can cause inflammation and pain throughout the body. Anyone can develop lupus, but it's most often seen in females aged 15–44 years, certain ethnic groups (African Americans, Asian Americans, Latinos, Native Americans, and Pacific Islanders), and in those with a family history of the condition (Lupus, n.d.).

With lupus, the inflammation often targets a person's skin, particularly on the face and scalp. Known as non-scarring alopecia, the hair on your scalp will gradually thin out, although a few people lose clumps of hair. Loss of eyebrow, eyelash, beard, and body hair also is possible.

Thyroid problems

The thyroid is the butterfly-shaped gland at the base of the neck that's responsible for producing the hormones that control metabolism. The American Thyroid Association (ATA) estimates that more than 12% of the U.S. population will develop a thyroid disorder during their lifetime and that women are five to eight times more likely to be diagnosed than men. 

The thyroid hormone also plays an important role in the development and maintenance of hair follicles. If your thyroid is overactive (hyperthyroidism) or if you have an underactive thyroid (hypothyroidism), it can trigger telogen effluvium, a type of temporary hair loss that usually happens due to stress or shock to the body.


Many people automatically link cancer to hair loss, but it's usually the treatment, not cancer itself, that's responsible for the change.

Hair loss is a common side effect of cancer treatments such as chemotherapy and radiation treatment. In fact, anagen effluvium, the loss of actively growing hair during the growth stage of the hair cycle, is sometimes referred to as chemotherapy-induced alopecia.

The hair loss can impact the scalp, eyebrows, eyelashes, and other body hairs; it usually begins within weeks of the start of treatment and may continue to progress gradually over the next 1–2 months.

Eating disorders

Individuals living with anorexia, bulimia, and other eating disorders commonly experience hair loss due to their malnourished state. When the body is in fight or flight mode, it needs to focus on the essentials, such as organ function and retaining muscle tissue. As a result, the hair growth cycle is disrupted.

A group of dermatologists in Italy found that telogen effluvium was one of the most frequent signs of starvation due to an eating disorder, preceded only by dry skin (xerosis) and downy peach fuzz known as lanugo-like body hair (Strumia, 2009). As with some other conditions on this list, eating disorders can shock the system into telogen effluvium.

Polycystic ovarian syndrome

Polycystic ovary syndrome (PCOS) is a hormonal disorder, which can result in missed menstrual periods and difficulty conceiving.

Because of the extra production of the androgen hormones, women will develop hair in places that are typically considered masculine, such as the face, neck, and chest. Conversely, PCOS can also lead to androgenic alopecia, which is thinning hair near the front of the scalp. This is known as female pattern hair loss.

Vitamin and mineral deficiencies

Other causes of hair loss relate to diet and subsequent vitamin and mineral deficiencies. Some research has pointed to a potential link between iron deficiency and telogen effluvium.

Anxiety disorders

Physical and emotional stress can manifest in the body in all sorts of ways, including hair loss. Emotional or physiological stress can result in the sudden onset of a temporary hair loss called telogen effluvium. Anxiety can also lead to two other types of hair loss: trichotillomania and alopecia areata (more on these soon).

Additional sources of hair loss

Hair loss can be the symptom or side effect of other medical conditions, but there are certainly cases in which hair loss is part of the actual diagnosis.


Have you ever noticed someone play with their hair, but to the point of plucking individual strands out of their head? This is known as trichotillomania or TTM.

Classified as a mental disorder under obsessive-compulsive and related disorders, trichotillomania involves recurrent, irresistible urges to tear hair follicles, inevitably resulting in hair loss. The hair pulling can occur within any region with hair, but the most common site is the scalp (72.8% of patients) followed by eyebrows (56.4%) and pubic region (50.7%), according to a study of nearly 1,700 people with self-reported TTM (Grant, 2016). 

Overall, it's estimated that 1–2% of adults and adolescents suffer from trichotillomania (usually females), and the chronic condition may come and go for weeks, months, or years at a time.

Burning scalp syndrome

Also known as trichodynia, burning scalp syndrome (as the name suggests) causes a burning, tingling, and itching feeling on the scalp. The condition is linked to a form of hair loss called alopecia areata. This type of hair loss causes the hair follicles to fall out in round clumps from the scalp and sometimes even the body.

Androgenic alopecia

Androgenic alopecia, or male-pattern baldness and female-pattern baldness, usually occurs gradually over time and in predictable patterns. With men, this means a receding hairline or bald spot, and for women, it's usually thinning hair along the crown of the scalp.

Androgenic alopecia develops as a result of genetic and environmental factors and is linked to dihydrotestosterone (DHT), a male hormone that is a natural byproduct of testosterone. Having a close family member with this type of hair loss increases your risk of having it as well.

Overall, the American Academy of Dermatology estimates that approximately 80 million people in the U.S. have pattern hair loss. This translates to around half of men aged 50 years old living with male pattern baldness, with the prevalence increasing with age. Female pattern baldness, which affects around 38% of women over age 70, is less common (Phillips, 2017). 

Traction alopecia

This type of hair loss is caused by repeated and severe stress on your hair follicles. This might sound familiar if you frequently wear your hair in a tight ponytail or bun or if styling braids or cornrows is part of your beauty routine. Those who repeatedly wear the same tight headgear, often for religious or professional reasons, may also be more prone to the condition. Rigorous shampooing, wearing a hat, and poor circulation have nothing to do with it!

With traction alopecia, hair loss usually begins with patches around the hairline or above the temples, depending on the shape of the hairstyle. In the early stages, it's even possible to identify broken hairs and redness around the hair follicles located at the base of each hair shaft. As the alopecia progresses, the hair follicles may become inflamed, also known as folliculitis, leading to pimples on the scalp.

Telogen effluvium

One of two types of drug-induced hair loss, telogen effluvium occurs when hair follicles are in the resting phase, which causes hair to fall out too early. Telogen effluvium can develop as a possible side effect of many widely used medications and supplements.

Alopecia areata

Alopecia areata is a disease where a person's immune system attacks their hair follicles, causing the hair to fall out in one of three distinctive patterns. With alopecia areata patchy, hair falls out in clumps that resemble the size and shape of a quarter. Alopecia totalis causes a total loss of hair on the scalp, and alopecia universalis causes a complete loss of body hair (NAAF, n.d.). Anyone can develop alopecia, but it's more likely to affect people who have family members with autoimmune disorders such as diabetes, lupus, or thyroid disease.

What can you do to remedy hair loss?

In many cases, the best way to treat illness-induced hair loss is to focus on treating the underlying condition. However, the severity and duration of the hair loss depend on the illness itself.

When telogen effluvium is the root of the hair loss, as it is with many illnesses in this article, the hair cycle should normalize, and hair should begin to grow back once the medication is reduced or stopped. For people who experience anagen effluvium hair loss due to cancer treatments, the hair will grow back but potentially with a slightly different texture or color.

When hair loss is part of a person's actual diagnosis, such as the case with androgenic alopecia, over-the-counter and prescription medications might be required to help prevent further hair loss and potentially even prompt hair regrowth.

If you believe that your hair loss or thinning is due to an existing condition, visit your healthcare provider for a medical history and blood tests to help determine the root of the problem. It's also important to discuss nutrition, hairdressing habits, and any other environmental factors that may play a role. And as noted earlier, many people living with alopecia can encounter a psychosocial toll, so don't be apprehensive about discussing the emotional side effects with your provider as well.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

July 27, 2020

Written by

Alexandria Bachert

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewer

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.