Abnormal hair loss

Also known as non-hereditary or temporary hair loss

Abnormal hair loss (alopecia) is temporary and stops when the cause of the hair loss is removed.

This page focuses on temporary or abnormal hair loss. Read about hereditary or normal hair loss.

Key points about temporary or abnormal hair loss

  1. Abnormal or temporary hair loss can be due to many causes, including nutritional deficiencies, health conditions, medicines, reactions to hair products, stress or pregnancy.
  2. In abnormal hair loss, you may notice your hair suddenly shed in a large amount, or shed a lot after combing or brushing, or that it is broken or unable to grow longer.
  3. See your doctor if you experience sudden hair loss at the same time as having fever, pain, weight loss, poor appetite, breathing problems, gut problems or skin problems.
  4. Treatment depends on the cause of your hair loss. Removal of the cause usually stops your hair loss. Talk to your doctor to find out the best treatment for you.
  5. Hair loss that is caused by a temporary cause can’t be prevented, but there are things you can do to help protect and keep your hair healthy.

What are the causes of abnormal hair loss?

Hair cycle of growth and rest

Like your skin and nails, your hair goes through a finely tuned cycle of growth and rest. There are 3 phases in a hair cycle:

  • In the first stage, your scalp hair is continually growing. This is called the anagen phase. In this phase, your hair grows about 1–2cm per month. About 90% of your hair is in this stage at any one time. It lasts between 2–5 years.
  • The second stage is call the catagen phase, which is when growth stops. About 1–3% of your scalp hair is in this phase at any one time. It lasts for 2–3 weeks.
  • The third stage is called the telogen phase. This is a resting phase and it lasts between 1–4 months. About 10% of your scalp hair is in this phase at any one time.

At the end of its resting stage, your hair goes through a shedding phase, which normally results in the growth of a new hair. When a hair is shed, it’s replaced by a new hair from the same hair follicle located just beneath the skin surface.

Disturbances to any phases of the hair cycle can cause abnormal hair loss.

Possible causes of abnormal hair loss include:

  • alopecia areata (an autoimmune condition affecting the hair follicles)
  • telogen hair loss (excessive hair shedding)
  • anagen hair loss (decreased hair growth)
  • trichotillomania (hair-pulling disorder)
  • skin conditions
  • traumatic hair loss.

Alopecia areata

Alopecia areata is an autoimmune disease, in which your immune system attacks your hair follicles, causing them to shrink and stop producing hair. This condition causes your hair to fall out abruptly, resulting in totally smooth, round patches about the size of a coin or larger on your scalp. The condition runs in families and may affect children and adults of any age.

Telogen hair loss

Telogen hair loss, also known as telogen effluvium, is a condition in which you shed too many hairs. Many of your hairs have been pushed into the resting (telogen) phase, which causes excessive shedding.

You may realise you’re shedding more hair than usual or handfuls of hair can be found on your pillow, comb, hairbrush or in the plughole. Causes include:

  • childbirth
  • fever or severe infection
  • thyroid disease
  • low iron
  • weight loss and malnutrition
  • excessive bleeding
  • major surgery or chronic illness
  • stress
  • low protein intake or a rapid weight loss diet
  • medicines such as contraceptives, anticoagulants and anticonvulsants.

Anagen hair loss

Anagen hair loss, also known as anagen effluvium, is when your hair is caught in the growing (anagen) phase. Your hair can’t grow longer and is broken. Your hair loss is sudden and can be caused by the following factors:

  • cancer treatment such as chemotherapy, radiotherapy or medicines that can suppress your immune system
  • short anagen syndrome – an inherited condition in which children can’t grow their hair long.

If you have anagen hair loss and it is caused by medicines, hair growth will return when the medicine is stopped.


Trichotillomania, also known as hair-pulling disorder, is a behavioural disorder that mainly affects adolescents. It can be associated with other mental health conditions such as obsessive compulsive disorder, depression or anxiety. This condition causes recurrent urges to pull your hair, which leads to hair loss.

Skin conditions

Skin conditions that affect your scalp can also cause hair loss. Examples include:

  • seborrheic dermatitis, eg, dandruff
  • psoriasis
  • lichen planus
  • discoid lupus erythematosus
  • tinea capitis – a fungal infection of your scalp
  • impetigo (school sores) – a bacterial skin infection.

If you have a skin condition that is causing hair loss, you may have other skin symptoms such as skin redness, rashes, scarring of your skin or skin itchiness.

Traumatic hair loss or traumatic alopecia

This may be due to the use of hair reshaping products (relaxers, straighteners, hot combs) or the persistent physical stress involved with tight rollers and tight braiding. Using these styling methods over a long period of time can lead to irreversible hair loss (your hair won’t grow back). If you have hair loss, stop these hair styling practices.

What are the symptoms of abnormal hair loss?

Hair loss may happen just to your scalp or to another part of your body, or to all hair on your body. You may notice increased hair shedding that happens suddenly, short or broken hair, or patchy hair loss, depending on the cause.

If your hair loss is caused by a medical condition that can also affect other parts of your body, you may also notice other symptoms such as skin problems, breathing problems, poor appetite, vomiting, fever, pain or gut problems.

See your doctor if you experience hair loss at the same time as any of the following symptoms:

  • skin problems
  • breathing problems
  • poor appetite or unexplained weight loss
  • vomiting
  • fever
  • pain
  • constipation or diarrhoea.

How is abnormal hair loss diagnosed?

Your doctor will ask you questions about your hair loss, including the pattern of your hair loss and whether you have any other medical conditions. Your doctor will also examine your hair and your skin. Investigations such as blood tests or skin testing may be done to find out the cause of your hair loss.

How is abnormal hair loss treated?

Treatment depends on the cause of your hair loss, eg, if you have an infection, the infection will be treated. If your medicines appear to be causing your hair loss, your doctor may stop your medicines. Hair loss that is caused by a medical condition will stop when you recover from the medical condition.

If you wish to slow or stop the progression of hair loss, there may be treatments available such as medicines or hair transplantation. You may also wish to use a wig or hair piece. Talk to your GP or doctor to find out the best options for you.

How can I prevent abnormal hair loss?

Most types of hair loss can’t be prevented. However, there are a few things you can do that may help keep your hair healthy and strong for longer, including to avoid:

  • tight hairstyles, such as braids, buns or ponytails
  • twisting, rubbing or pulling your hair
  • hair lotions that are heavily perfumed
  • excessive heat treatments.

What support is available with abnormal hair loss?

Hair loss can be distressing and difficult to accept initially. Talking with others who have experienced hair loss may help. If you need to talk to someone, ask your doctor about counselling sessions available in your area or for a referral to a counsellor.

Below are also some support groups you may find helpful.

NZ Alopecia Facebook support group
NZ Alopecia website Information from fellow New Zealanders living with alopecia. Links to support groups, personal experiences through to information about the wig subsidy.
Wigs and hairpieces subsidy Information from the Ministry of Health regarding wigs and hairpieces subsidy for people who suffer from serious hair loss because of a medical condition or from certain cancer therapies.

Learn more

The following links provide further information about abnormal hair loss. Be aware that websites from other countries may have information that differs from New Zealand recommendations.   

Hair loss DermNet NZ
Hair loss (alopecia) HealthInfo Canterbury, NZ
Wigs and hairpieces subsidy Ministry of Health, NZ
Hair loss NHS, UK


  1. Hair loss DermNet NZ
  2. Alopecia Patient Info, UK
  3. Hair loss NHS, UK
Credits: Health Navigator Editorial Team.