16 Possible Causes of Hair Loss

by | Hair Transplant

Excessive amounts of falling hair can be unsettling. It is frustrating when you are not sure of the reason behind this symptom. The causes of hair loss differ for everyone and it is in knowing what it is that you will be able to find a proper solution.


For some people, the kind of hair loss they experience is progressive and it is a phenomenon written in their DNA. This condition is called androgenetic alopecia, but it is commonly known as pattern hair loss because hair sheds in a specific shape.

In men, the first noticeable sign is a receding hairline or a bald spot at the top (crown) of the head. Women experience a generalized thinning over the entire scalp or a widening part.

The culprit behind this type of hair loss is dihydrotestosterone (DHT) which can shrink the follicles and shorten the hair’s life cycle. Baldness occurs mainly among men because they typically have more testosterone than women.

Treatments to block DHT may help prevent hair loss. Meanwhile, medications and treatments like hair transplant surgery can restore hair volume. Without treatment, you will continue to lose hair. Early intervention often makes for favourable results.


Nearly everyone will experience hair loss as they age. At some point, the hair’s growth rate eventually slows down while some follicles stop producing hair entirely. This gradual change will cause our scalp hair to become thin. As a result, hair strands become smaller, and they also lose colour.

How hair loss progresses in males and females is akin to androgenetic hair loss. Men typically start losing it on the temples or the crown, while it’s more widespread in women.

Treatments like medication, Platelet Rich Plasma (PRP) injections, hair supplements and Low-Level Laser Therapy (LLLT) are some measures to help boost hair growth. Surgical hair restoration is also an option for suitable candidates.

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Hormonal Imbalance

Women who have recently got off the pill or have just had a baby are exposed to hormonal shifts that affect hair growth. Specifically, higher estrogen levels make the hair thicker and fuller, but hair falls out when estrogen levels drop, as with childbirth. In addition, health conditions that cause hormonal imbalance in women, such as Polycystic Ovarian Syndrome (PCOS), pose a higher risk of hair loss.

Fortunately, excessive hair shedding should stop as your body adjusts to your new estrogen levels.

But in some cases, treatment is needed to help restore hormonal balance.

Alopecia Areata

Alopecia areata is a disease that develops when the body’s immune system attacks its hair follicles, which triggers patchy hair loss anywhere in the body. Abrupt hair shedding may occur on the scalp, characterised by round or oval patches.

Currently, there is no cure for alopecia areata. Some treatments may help hair grow back and prevent future hair loss. This condition, however, can be unpredictable which means there may be some trial and error until you find a treatment that works for you.

Interventions can run the gamut from alternative therapies, medication, steroid injections, light therapy to oral treatments. You may need more than one treatment to see a difference. Unfortunately, it is also possible for hair to grow back and fall out again.

Cancer Treatment

Hair loss is a common side effect of cancer treatments such as chemotherapy, targeted therapy or radiation therapy. The reason is that the medication used inevitably harms the healthy cells while they kill off the cancer cells in the body. Hair does not fall out as soon as you start treatment, instead, it often takes several weeks or cycles before it starts to shed.

Chemotherapy may cause hair loss all over your body and the amount of hair fall will depend on the drug used, dosage and route (e.g. oral, intravenous, or topical). Meanwhile, radiation and targeted therapy affect the hair on the body part where the treatment is focused.

Hair typically grows back once you finish the entire course of treatments. New hair may initially develop as a thin fuzz. Some follicles are also expected to enter the active growth period faster than others. In such cases hair length may vary causing hair growth to look patchy at first but hair should eventually settle into a more regular growth pattern. The texture may differ from what it was before.


Chemotherapeutic drugs may be a common cause of drug-induced hair loss but other medications also have side effects. Typically shedding often occurs within three months after you start taking a particular drug. It begins with hair thinning leading to patchy hair loss, which is more apparent on the top of the head.

Some medications that can cause hair loss include blood thinners, gout medications, blood pressure medications, antidepressants and anticonvulsants. Fortunately, this type of hair loss is usually temporary. It does not however takeaway from the fact that its effect on your appearance may bother you. You can however speak with your doctor if you wish to take a different medication to minimise or avoid the excessive hair shedding.


Research on mice show that stress hormones inhibit the cellular development necessary for hair growth.

This stress-related hair loss is called Telogen Effluvium, characterised by the abrupt onset of hair loss. Hair loss often begins about three months after the predisposing event. It prematurely pushes the hair follicles into the resting phase. It takes about three months for the cycle to complete and for the hair to shed. It does so in a diffuse pattern and it is temporary.

Whilst there is no proven way to prevent or stop an episode of telogen effluvium, it is known to resolve on its own with time. There are some things that may help support overall hair health, such as eating a healthy balanced diet, tending to your emotional health and practising coping mechanisms.

Hair Products

If you are fond of colouring, perming or chemically straightening your hair, these practices can be damaging. Depending on the products used and the ingredients found in them, some can cause temporary hair loss.

It will help if you practice caution with the chemicals found on some products as some can be very harsh, which can cause your hair to weaken. With extensive damage, your hair may eventually fall out, particularly if the products are misused.

Permanent damage is possible if you keep using the wrong products. Once the hair follicle is damaged, hair can no longer grow from it. So you may get bald spots as a consequence of damaged follicles.


Traction alopecia is the kind of hair loss caused by tight hairstyles that can cause your hair to break or fall out. Unless you switch your hairstyle or let your hair down for a change, you will likely experience permanent hair loss.

Dr Tyng Tan - Hair Loss Causes - Hairstyle

Scalp Infection

It’s also possible that some infectious agents are the culprits behind hair loss. These infection-related conditions include:

  • Ringworm – This is a fungal infection that begins as a small pimple that progressively expands in size, leaving scaly patches of temporary baldness. When the fungus gets into the hair fibres, the affected hairs become brittle and break off easily, leaving bald patches of skin. 
  •   Folliculitis – This refers to the inflammation of hair follicles. In severe cases, the inflammation can permanently damage the follicles, resulting in small bald patches.
  •   Piedra – This is another fungal infection that targets the hair fibres, creating hard nodules in their place. Typically, this infection is relatively benign, but it can weaken the hair fibres and cause hair loss.
  • Seborrheic Dermatitis – This skin condition can affect any part of the body, but it can cause temporary hair loss when it targets the scalp. Dermatitis is often associated with scaly, inflamed and sometimes oily skin that can be itchy or painful to touch.

Scalp Psoriasis

This condition occurs when the immune system malfunctions and tells the skin cells to overgrow. Hence, it piles up within days instead of a gradual process that takes weeks resulting in a buildup on the skin’s surface. As a result, the affected area will have fine scaling that looks like thick, crusted plaques covering the entire scalp or parts of it.

Scalp psoriasis can result in hair loss, but regrowth is possible once the problem clears. Relief may take some time, but you can ask your dermatologist for tips on preventing further hair loss.

Hair Pulling

Clinically referred to as Trichotillomania, this behaviour is a type of mental disorder that involves a recurrent and irresistible urge to pull out hair from your scalp or other hair-bearing areas. Hair pulling from the scalp can leave patchy bald spots if done repeatedly. In addition, it’s possible to regrow hair in the affected areas if the hair follicles are not destroyed.

Trichotillomania is a long-term disorder. But you can avoid permanent damage if you acknowledge that you have a problem and seek help to overcome triggers.

Scarring Alopecia

Scarring alopecia encompasses a group of hair loss disorders in which the follicle is irreversibly destroyed and replaced by scar tissue. In effect, the hair is unable to regenerate. This problem may be caused by thermal burns, metastatic cancer, trauma or radiation. Catching this condition early may prevent further hair loss.

Sexually Transmitted Infection

A sexually transmitted infection (STI) left untreated can lead to hair loss. However, unlike other STIs, syphilis is known to cause patchy or diffuse hair loss on the scalp, eyebrows, beard, and other hair-bearing areas. This symptom is common in secondary syphilis, which develops when the disease is untreated in its primary stage.

Syphilitic alopecia has three types: the classic patchy “moth-eaten” alopecia, generalized hair thinning of the hair or a combination of both. Hair regrowth is possible if syphilis is treated.

Thyroid Disease

Problems with your thyroid such as hyperthyroidism and hypothyroidism are linked to hair thinning and hair loss. The type of hair shedding can affect the entire scalp, with the hair appearing uniformly sparse. Hair will usually grow back with successful thyroid disorder treatments. Although it may take several months, the coverage may not be as it was before.

Thyroid Disease

Problems with your thyroid such as hyperthyroidism and hypothyroidism are linked to hair thinning and hair loss. The type of hair shedding can affect the entire scalp, with the hair appearing uniformly sparse. Hair will usually grow back with successful thyroid disorder treatments. Although it may take several months, the coverage may not be as it was before.

Nutritional Deficiencies

Nutritional deficits, especially among nutrients critical to hair growth can result in noticeable hair loss. This problem impacts both hair structure and hair growth. Too little protein, zinc, biotin, fatty acids, vitamin D and iron can compound the impact on your hair. Diet-related hair loss is reversible if you resume a proper diet.

With the knowledge you have amassed with regard to the causes of hair loss that vary for each individual, we hope that this encourages you to seek professional help. We conduct a thorough assessment to ensure that you are the right candidate for surgery at our clinic. Alternatively, we can also advise you on appropriate measures to take. For a thorough evaluation, we invite you to get in touch with our team now to book a non-obligatory consultation.

Dr. Tan Tyng Yuan
BSc (Hons), MBBS (London), Grad. Dip. Dermatology (UK), Dip. AAAM (USA), Grad. Fellow in ISHRS (International Society of Hair Restoration Surgery)

About Dr Tyng Tan

Dr Tyng Tan has over ten years of experience treating male pattern baldness with the minimally invasive, non-strip method known as FUE (Follicular Unit Extraction) Hair Transplantation.

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