Hereditary hair loss

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Hair cycle of growth and rest

Like your skin and nails, your hair goes through a finely tuned cycle of growth and rest. Hair loss can occur at any time in the cycle.

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, a 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 your skin surface.

Male or female hereditary hair loss is caused by genetic or hormonal influences. It is also called androgenic alopecia because it is affected by the hormones called androgens. These are present in both men and women, but in different quantities.

Your risk of hereditary hair loss increases if you have relatives who have experienced hair loss. Your genetic blueprint for hair loss will affect things like:

• how old you are when hair loss begins
• how fast you lose hair
• the pattern and extent of your hair loss/ baldness.

Male hereditary hair loss

Hereditary hair loss in males is also known as male pattern baldness. It is more common with increasing age. The condition affects different populations at different rates and accounts for 99% of hair loss in men. It affects half  the male population by the age of 50.

Hair loss starts in men from about the age of 30, but can occur at any age past puberty. How quickly or slowly baldness develops, and the pattern of hair loss, appear to be determined by the genes you inherited from your parents.

Your genes affect how sensitive your scalp is to a hormone called dihydrotestosterone (DHT), which shortens the growth phase of your hair. Your hair follicles also become smaller in response to DHT and you subsequently produce fewer and finer hairs.

Female hereditary hair loss

Female hereditary hair loss is known as female pattern baldness. Its cause is not clearly understood. It can affect women in any age but occurs more commonly after menopause. It usually begins about the age of 30, becomes noticeable about the age of 40, and more noticeable after menopause. By the age of 50 at least a quarter of women experience some degree of hair thinning.

It is also thought that female hereditary hair loss is influenced by genetics and the androgen hormones, although the link is not as strong as in male hereditary hair loss.

In female hereditary hair loss, finer hairs with less colour are produced, and hairs in the resting (telogen) phase fall out more easily.

Other forms of hair loss

Hair loss that is not hereditary is considered to be abnormal. It may be caused by:

• pregnancy
• hormonal or other medicines
• severe nutritional deficiencies
• chemotherapy
• autoimmune disorders
• an underactive or overactive thyroid gland
• scalp trauma, including reactions to hair care products and hair grooming methods
• stress
• a condition that involves hair-pulling (trichotillomania).

Read more about abnormal hair loss.

The pattern of hair loss is different in male hereditary hair loss from that in female hereditary hair loss.

Male pattern hair loss

In males, baldness usually begins with progressive thinning at the hairline (receding hairline), followed by the appearance of a thinned or bald spot on the crown of your head.

Female pattern hair loss

Women with hereditary baldness rarely develop bald patches. Instead, you experience a general thinning of their hair, especially over the top of your head or crown, while maintaining a frontal hairline.

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. No tests are needed to diagnose hereditary hair loss, but blood tests may be done to rule out other conditions that can cause hair loss.

Losing your hair slowly is a normal part of the ageing process for most men and some women. Treatment is not usually necessary. However, hair loss that occurs rapidly or early in life can be distressing. If you wish to slow or stop the progression of hair loss, there are treatments available.

Treatments for hair loss include:

• medicines, both local and oral
• wigs, hairpieces or hair transplantation.

Hair loss that is caused by a temporary situation such as illness, medication, stress or insufficient iron will stop when the cause is resolved. Read more about abnormal hair loss.

Medicines for hereditary hair loss

Finasteride and minoxidil are the main medicines currently available to treat hair loss. However, they are not subsidised in New Zealand, so you need to pay for them yourselves.

Medicines that are used to treat hair loss provide different results for different people. It's also not possible to predict who may or may not benefit from treatment.

Finasteride

This is a prescription-only treatment for hereditary hair loss in men. It is available as a tablet. It works by blocking the conversion of testosterone to dihydrotestosterone. The hair follicles then are not affected by this hormone and will not shrink. Treatment needs to be continued for at least 6 months once started. If successful, the treatment is continued to maintain the effect.

Talk to your doctor to find out whether finasteride is suitable for you. Women should not take finasteride as a treatment for hair loss. 

Hair clinics may arrange prescriptions for both local and oral treatments. Read more about finasteride.

Minoxidil topical lotion

Minoxidil is a rub-on treatment that can be bought from your local pharmacy. It can be used by both men and women. It needs to be applied twice daily to the scalp while it is dry. Minoxidil is more effective in the earlier stages of hair loss. Treatment needs to be continued for at least 6 months once started. If successful, treatment is continued to maintain the effect. Sometimes, a low-dose minoxidil tablet can also be prescribed for hair loss.

Talk to your doctor to find out whether minoxidil is suitable for you.

Nutritional supplements

Various supplements are often advised by health clinics. However, the only useful study on a supplement featured saw palmetto extract and the results were inconclusive. 

If any you want to try dietary supplements, those most likely to help are vitamins A and C, biotin, zinc and iron.

Wigs, hair pieces or hair transplantation

Cosmetics such as hair sprays or hair colouring products, wigs and hair pieces can be effective to hide area with hair thinning. Hair transplantation has become more popular but not everyone is suitable for this procedure and it is expensive. Talk to your doctor to find out whether these treatments are suitable for you.

The Ministry of Health also provides a wig and hairpieces subsidy. Read more about the wigs and hair pieces subsidy(external link) to find out if you are eligible.

Hereditary hair loss is part of your genetic blueprint. While there isn't anything you can do to change your genes, there are a few things you can do that may help keep your hair healthy and strong for longer.

Dietary protein is important

Hair is made up of a form of protein (keratin), the same one found in fingernails and toenails. There are also a number of other chemical substances such as calcium, copper, zinc and iron as well as a small amount of fat in hair.

Everyone, regardless of age, should eat enough protein to maintain normal hair production. Protein is found in meat, chicken, fish, eggs, some cheese, dried beans, tofu, grains and nuts.

Be gentle with your hair

• Avoid tight hairstyles, such as braids, buns or ponytail.
• Avoid twisting, rubbing or pulling your hair.
• Avoid hair lotions that are heavily perfumed.
• Avoid excessive heat treatments.
• Avoid long periods in the sun.

Hereditary hair loss is a normal part of the ageing process. However, when baldness occurs suddenly or early in life it can be distressing. Hair loss is particularly upsetting for women. 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(external link) Facebook support group
NZ Alopecia website(external link) Information from fellow New Zealanders living with alopecia. Links to support groups, personal experiences through to information about wig subsidy.
Wigs and hairpieces subsidy(external link) 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.