Why am I Losing my Hair?


Zoe Miller, BSc, MD, MBChB
May 13, 2024
Take-home points:
  • Hair loss is completely normal.
  • Excess hair loss that leads to balding is usually caused by hormonal changes or stress in people with certain genes.
  • Excess hair loss can fracture peoples’ self-image and confidence.
  • Some types of hair loss are reversible, but not all.
  • Hair loss treatments range from dietary, medical, surgical and counselling.

Why am I losing my hair?

Are you wondering why you're losing your hair? Have you noticed changes to your hairline? Or that your hair is thinning in places? You may be wondering what’s causing you to lose your hair, and if there’s anything you can do about it.

In this article, we’ll talk about the causes of hair loss, different types of hair loss, and how to deal with losing your hair.

Understanding hair loss

Most people don’t need to think much about hair growth—it just happens. Yet beneath the simplicity is a complex cycle with four stages: growth (anagen), transition (catagen), resting (telogen), and shedding (exogen) phases.1 Most of time our hair is in the growth stage, where it stays for several years before it falls out and is replaced.

Hair loss relates to the fourth stage, when old hairs fall out to make way for new ones. It’s completely natural to lose between 50–100 hairs a day and barely notice.2 It’s only when you start losing more hair than you’re growing that you might worry about hair loss and seek treatment.

Hair loss can be reversible depending on whether it has been caused by scarring. It’s usually the scarring that prevents the hair from growing back, causing permanent hair loss. Let’s explore the different types of hair loss and what causes them in more detail.

Common types of hair loss and their causes

Male pattern hair loss

Male pattern hair loss (better known as male pattern baldness or androgenetic alopecia) is one of the most common types of hair loss. It can begin as early as the late teens or early twenties but is more prevalent with ageing. By the age of 50, up to 50% of men have signs of male pattern baldness such as thinning, a receding hairline, or balding.3 This type of Hair loss tends to be permanent.

The tell-tale signs of male pattern baldness include:

  • A receding hairline.
  • Hair loss around your temples.
  • Hair loss on top of your head (your crown).

In most cases, the trigger for male pattern hair loss is hormonal changes. The sex hormone dihydrotestosterone (DHT) binds to the hair follicles and causes miniaturisation, when the hair follicle constricts and makes it harder for hair to grow. This leads to thinner, finer hairs, and hair loss. Genetics play a key role in male pattern hair loss, too. People with a high sensitivity to DHT, which tends to run in families, are more prone to hair loss than people with low sensitivity to DHT.

The following health conditions are also linked to an increased risk of male pattern baldness:

  • Obesity.
  • Prostate cancer.
  • High blood pressure.
  • Heart disease.

Alopecia areata

Alopecia areata affects around 2% of the UK population and is caused by an autoimmune disorder—when your immune system attacks your body. For reasons unknown, white blood cells start to attack the hair follicles and interfere with the natural hair growth cycle.

In alopecia areota, hair loss is unpredictable and patchy.4 Hair often falls out in small patches around the size of a coin, although wider areas of the scalp can be affected. In some cases, people lose all the hair on their scalp (alopecia totalis) or their entire body (alopecia universalis).

Alopecia areata can affect anyone, regardless of age, gender, or race, but is more common in people younger than 30. Individuals with other autoimmune diseases, like thyroid disease and type 1 diabetes, are also more likely to develop this type of hair loss,5 and stress may be a trigger.

Unfortunately there’s no cure for alopecia areata, and people tend to continue losing their hair in an unpredictable way.

Telogen effluvium

In telogen effluvium, more hairs than normal move into the resting (or telogen) stage of the hair growth cycle. This means hair sheds more quickly than it otherwise would, leading to hair loss.6 Hair thinning and increased hair shedding are the main signs of telogen effluvium—often all over the scalp.

In most people, telogen effluvium happens after a stressful or traumatic event (although for some, the cause is unclear). Examples include:

  • Significant weight loss.
  • Surgery.
  • Serious injury.
  • Childbirth.
  • Thyroid disease.
  • Certain medications.

Hair loss doesn’t usually happen until several months after the event, as this is how long it takes for hair to fall out. Hair should regrow within 6 months, but in some cases, it takes much longer.

Other types of hair loss

There are many types of hair loss less common than the ones we’ve discussed. These include:

  • Hair pulling disorder (trichotillomania): This is a condition where someone can’t stop themselves from pulling their hair out. It involves hair on the head, eyebrows, and/or eyelashes, leading to hair loss in these areas. This repetitive behaviour is often linked to stress.
  • Traction alopecia – A type of hair loss caused by tight hair styles that’s especially common in black people with tight, curling hair who wear their hair braided for long periods of time.7
  • Anagen effluvium - A form of nonscarring alopecia commonly associated with chemotherapy.

Although not a specific type of hair loss, medical conditions and vitamin deficiencies may also limit hair growth and reduce hair quality.

Hair loss treatments

Whether hair loss can be treated effectively depends on the cause.

Hair loss caused by a medical condition, nutrient deficiency, or stress, is most likely to be reversible. In these cases, consulting a health professional to address these health concerns, whether physical or mental, is a good idea. Many people suffering from hair loss due to ongoing stress, anxiety, or hair pulling behaviours will benefit from attending counselling as part of their hair loss treatment.

There are several medical treatments available for hair loss:

  • Finasteride: This prescription medication works by blocking DHT, stopping the hormone from binding to the hair follicles. Finasteride is available as a tablet and in shampoo/spray form. It is particularly effective for male pattern baldness.
  • Minoxidil: This over-the-counter medication can be applied directly to the scalp, usually as a shampoo. It works by increasing the flow of blood and nutrients to the hair follicles, which can stimulate new, healthier hair growth. Like finasteride, it is particularly effective for male pattern baldness.
  • Steroid injections: This treatment is used only for alopecia areata and involves injecting corticosteroids directly into the scalp to reduce inflammation and suppress the immune response.
  • Ritlecitinib: An immunosuppressant that, similar to steroid injections, targets the immune pathways involved in alopecia areata. It is currently an investigational drug pending approval.
  • Surgical treatments are also an option for hair loss:Hair transplants: This involves moving hair follicles from one part of the body (known as the donor site) to a bald or balding area (recipient site) of the scalp. This procedure is typically performed under local anesthesia.
  • Laser therapy: A non-invasive treatment option that works by exposing the scalp to low levels of laser light, which is thought to promote cellular activity within hair follicles.

We recommend consulting with a healthcare professional before starting any treatment for hair loss. Remember, not all treatments are suitable for everyone, and some may have side effects. If you do not want to use these treatments but do not like the visual appeal of hair loss and baldness, wigs or hairpieces are of course a fantastic options that can boost confidence.

  1. Hoover E et al. Physiology, Hair. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499948/ (Accessed April 2024)
  2. NHS. Hair loss. Available from: https://www.nhs.uk/conditions/hair-loss/#:~:text=It (Accessed April 2024)
  3. Cranwell W, Sinclair R. Male Androgenetic Alopecia. Available from: https://www.ncbi.nlm.nih.gov/books/NBK278957/ (Accessed April 2024)
  4. NICE. Alopecia areata: How common is it? Available from: https://cks.nice.org.uk/topics/alopecia-areata/background-information/prevalence/ (Accessed April 2024)
  5. British Association of Dermatologist. Alopecia Areata. Available from: https://www.bad.org.uk/pils/alopecia-areata/ (Accessed April 2024)
  6. Alopecia UK. T‌elogen Effluvium. Available from: https://www.alopecia.org.uk/telogen-effluvium (Accessed April 2024)
  7. Pulickal JK et al. Traction Alopecia. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470434/ (Accessed April 2024)

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