Losing hair (alopecia) is a common phenomenon in both men and women and there are various causes for hair loss.

The person starts missing his hair, especially at that time when he has lost a substantial amount of it. One yearns for that thick growth, which he once sported, but many do not do anything about the hair fall nor do they try to identify the causes.

There are effective hair loss treatment options available for men and separate treatments for women to stop hair fall. Ideally, you should take preventive measures to stop this loss as a routine measure and ensure that your hair gets enough nutrition.

Some causes of hair loss are common both in men and women while some causes are attributed to hair loss in women alone.

Understandingly, we all wish for that thick growth of hair on our heads and look at the mirror every morning to see if that receding hairline has stopped progressing. We worry about the reasons for the hair falling out and wish we could do something about it.

  • Some people experience hair growth back without doing anything.
  • Others have their hair growing back after taking treatment.
  • In some, the hair does not grow back even after making efforts and taking treatments.

What differentiates the three sections of the people above are the reasons, which have caused hair loss.

It is, therefore, necessary that you first educate yourself on the various causes of why you could be losing your hair and what you can possibly do about it. If you are losing hair, you must see a dermatologist who specializes in this fraternity. What he will do is identify the type of hair loss and treat it accordingly.

Understanding the Causes of Hair Loss in Men, Women, and Children

I have listed here eleven causes of hair loss, most of which can be reversed and hair growth restored. You could be losing hair due to some serious reasons such as some health conditions or medications and correcting those problems can stop your hair loss and restore hair growth.

There are varieties of diseases that can cause your hair to fall. The reason attributed to this is stress-related. This hair loss is temporary and the hair does grow back once the disease is cured. Let us take the important and common ones.

1. Thyroid disease

Severe and long-standing underactive (hypothyroidism) and overactive thyroid (hyperthyroidism) can cause loss of hair, which is usually diffuse all over the scalp. Mild hyperthyroidism or hypothyroidism rarely causes you to lose hair.

Hypothyroidism causes you to lose hair and gain weight while hyperthyroidism causes you to lose hair and lose weight.

Once the thyroid issue is successfully treated, hair grows back, but it may take several months.

At any given time, about 85 percent of your hair is in the growing or the anagen phase and about 10 to 15 percent are in the resting phase.  The growth of the hair depends heavily on the normal thyroid function.

Abnormal levels of thyroid hormones disturb the hair cycle and the hairs in the growing phase are thrown into the resting phase leading to the loss of more hair and decreased growth of hair.

Hair loss due to thyroid disease occurs several months after the onset of the thyroid disease. This may mistakenly lead you to believe that the loss is due to the treatment, which is not the case.

However, the hormone levothyroxine given for treating an underactive thyroid can cause some amount of hair loss. This is temporary, seen during the first month of the treatment, and occurs more in children than in adults. This hair fall stops after the treatment is further continued and the levels of the thyroid hormones stabilize.

2. Lupus

Lupus is a chronic autoimmune disease, which causes inflammation of any part of the body (skin, joints, and/or organs). Hair loss can often be an early sign even before the doctor has diagnosed this disease.

Skin, particularly on the face and scalp is usually involved. Lupus of the scalp can cause your hair to thin out and you could lose clumps of hair subsequently. Your hair can become brittle and break off. Loss of eyebrows, eyelashes, beard, and body hair may also occur.

In the majority of the cases, the hair grows back once you get your lupus treated. However, some people develop discoid (round) lesions on the scalp and subsequent scarring. In such cases, hair loss is permanent.

3. Uncontrolled diabetes and hair loss

Diabetes, as well as medications taken for diabetes, can cause hair loss in men and women. Diabetes can cause loss of hair in three ways.

Firstly, diabetes compromises the immunity of a diabetic, more so when the blood sugar levels are not controlled. The reduced immunity makes the person susceptible to various infections including the ringworm infection of the scalp. This is more common in type 1 diabetes, which is found mainly in children.

Secondly, type 2 diabetes reduces the efficacy of the circulatory system in the body, which hampers the circulation to the various parts of the body. The hair follicles, too, receive less blood supply and nutrition. This causes the hair roots to weaken and hair to fall.

Thirdly, diabetes disrupts the functioning of the endocrine system, which comprises of many hormones. The normal secretion of the hormone, androgen sex hormone, too is disturbed. Androgens play a significant role in maintaining the growth and health of the hair follicles. Uncontrolled diabetes with its high blood sugar levels causes disturbed androgen levels, which lead to weakened hair follicles and hair loss.

Hair loss due to diabetes can be controlled and reversed if you keep your sugar levels under control at all times by sticking to the diabetic diet, having sufficient physical exercise, and maintaining healthy lifestyle habits.

Metformin used in the treatment of type 2 diabetes is known to cause hair loss. In such cases consult your doctor and ask him for an alternative drug.

4. Polycystic ovarian syndrome – cause of hair loss in women

About 67% of the women who suffer from alopecia or hair loss also have polycystic ovarian syndrome (PCOS).

Women who have PCOS have higher than normal androgen levels in their body. Androgens are male sex hormones such as testosterone.

Testosterone converts to Dihydrotestosterone (DHT), which attaches to the hair follicles and makes them go from the growing phase into the resting phase sooner.

DTH also causes the hair follicle to stop producing new hair. Initially, you will start noticing thinning of hair, and with each cycle, the thinning progresses.

However, the hair follicle stays alive and can be reactivated to produce new hair with treatment.

5. Ringworm (Fungal infection) of the scalp: Cause of hair loss in children

Ringworm of the scalp also called tinea capitis, mainly causes hair loss in children.

Ringworm of the scalp is contagious and spreads through the use of contaminated towels, brushes, combs, and by touch from furniture, bed sheets and pillow covers over prolonged periods. It is, therefore, common to see children in the same house or school suffering from this fungal infection.

The fungus enters the hair shaft making it brittle leading to the hair easily falling off. Ringworm of the scalp causes patchy alopecia with the bald patches looking inflamed and scaly. These inflamed patches may develop painful pustules, which get infected and cause fever and swollen lymph glands in the neck.

There may be oozing and if not treated, scarring can develop. Scarring can lead to permanent hair loss. However, if treated early before scarring sets in, hair loss is reversed.

6. Cause of dramatic weight loss

Sudden significant weight loss can traumatize and stress your system, which can result in thinning of hair.

The weight loss could be due to rigid dieting causing nutritional deficiencies. Another cause could be eating disorders such as anorexia nervosa or bulimia.

However, this hair loss is corrected after six months. Ideally, if you have to lose weight, it should be gradual and not sudden. Abrupt weight loss can have other undesirable effects on the body as well.

7. Post pregnancy hair loss causes

Pregnancy and delivery of the baby are other examples, which stress your body system and can cause temporary loss of hair. This type of hair loss after labor is called telogen effluvium.

Excessive shedding of hair one to five months after childbirth occurs in 40 to 50% of women.  This occurs because during pregnancy increased number of hairs (about 60%) goes into the resting phase.

Hair loss does not occur during pregnancy because of the high levels of hormones (estrogen) during that period. Estrogen causes your hair to stay in the growing phase (anagen phase) and stimulates the growth of new hair, giving you an abundant amount of hair on your head.

After childbirth, the hormone levels stabilize and the normal hair cycle begins with the hair fall delayed during pregnancy being initiated.

This hair loss is temporary and you regain your normal hair growth within six to twelve months after delivery.

This hair loss is not serious as you experience thinning of hair and no bald spots are seen.

If excessive shedding of hair during pregnancy is noticed, it could most likely be due to the nutritional deficiency of vitamins and minerals.

8. Female hormonal imbalance

Just as hormonal changes during pregnancy and post-labor cause changes in the hair cycle, there are other instances in a woman’s life, which can cause hair loss.

Taking birth control pills can cause you to lose hair. It is called telogen effluvium and is seen more in women with a family history of hair loss.

Stopping the pill can also cause hair loss irrespective of the family history status. This is caused due to the sudden drop in the estrogen levels

Similarly, women who attain menopause when hormonal balance changes, experience hair loss.

These instances of hair loss occur because the androgen receptors on the scalp are activated and as explained above, androgen hormones convert the hair in the growing phase to go into the resting phase. They also inhibit the hair follicles to produce new hair by shrinking the hair follicles.

What should you do?

If an oral contraceptive pill is causing hair loss, consult your doctor and ask for an alternative birth control option.

The American Hair Loss Association (ALHA) recommends that all women should only use low-androgen index birth control pills.

Those who have a family history of hair loss should use other birth control options and avoid using the pill.

If stopping your birth control pill has caused hair loss, don’t worry. It is temporary. Your hair will grow back.

9. Medical causes of hair loss: Drug-induced hair loss

Certain medicines for treatments of diseases and health disorders can cause hair to fall leading to thinning of hair and baldness. The degree of drug-induced hair loss depends on the type of drug used, its dosage, and your sensitivity to the drug.

How do these drugs cause hair loss?

Scalp hair follows a normal cycle of growth and fall. The anagen phase is the phase of active hair growth and lasts for two to six years. This amount of time is determined by your genetic disposition. About 85% of your hair is in this phase at any given time.

The telogen phase follows the anagen phase and is the phase when your hair stops growing and rests. This phase lasts for about three months after which the hair starts falling out.

Drug-induced hair loss is of two types: telogen effluvium and anagen effluvium.

Telogen effluvium causes hair follicles in the anagen (growing) phase to go into the telogen phase causing them to fall out early. This type of hair loss due to medications is the most common and sets in about three to four months after taking the drug.

Anagen effluvium affects hair that is in the anagen phase (growing phase). It prevents the epithelial cells in the hair matrix from dividing and forming new cells. This type of hair loss is fast and starts occurring within a few days to a few weeks after starting the medication.

This type of drug-induced hair loss is most commonly seen in people taking chemotherapy treatment for cancer, wherein almost all the hairs on the scalp and other parts of the body are lost.

Drugs used for the following diseases and health conditions can cause hair fall.

Once the medicines and treatments are stopped or completed, hair loss is reversed.  The American Hair Loss Association gives an exhaustive list of drugs.

10. Other lifestyle causes of hair loss

  • Poor nutrition leads to falling levels of iron and proteins in the body causing less nutrition to reach the hair, which contributes to hair loss. Proper nutrition regains hair growth as the cause of hair fall is removed.
  • Excessive brushing, dyeing, and bleaching of the hair also cause your hair to fall.
  • As age advances, losing hair is natural.

11. Hereditary cause of hair loss

In people who develop hair loss and baldness due to a hereditary trait in the family, the hormone DTH present is more than normal levels. This causes erosion of the hair follicles. Hair falling out due to this cause is the most difficult to treat.

The wrong notion about dandruff and hair loss

Dandruff is clumped dead skin cells of the scalp, which are replaced by new cells. By itself, dandruff does not cause your hair to fall and is not included in the list as one of the causes of hair loss.

However, due to itching caused by it, one does tend to scratch the scalp vigorously. This leads to inflammation of the skin of the scalp and subsequently to loss of hair.