A sudden physical trauma or a sudden emotional stress can cause large amounts of your hair to shed. For example:
Major illness
Sudden loss of blood
Major surgery
Childbirth
Severe infection
High fever
Severe emotional stress
Crash diets – in particular diets that are lacking in protein
Certain medicines – for example, beta-blockers, NSAIDs, ibuprofen, retinoids, birth control pills, some antidepressants and calcium channel blockers.
This can lead to the loss of as much as half to three quarters of the hair on your head. There may also be a delay and you may not notice the hair loss for weeks or even months after the trauma or stress that caused it which may lead you to think that there maybe another reason for this hair loss. Having handfuls of hair coming out of your head when you shampoo, brush or just run your hand through your hair can be alarming for many people, but try not to worry and expect this shedding to decrease over a period of about 6 to 9 months.
Some women between the ages of 30 to 60 can suffer a thinning of the hair that affects the entire scalp. This hair loss can be heavy at first and then gradually slow or stop. The cause of this type of hair loss is unknown.
If the hair loss is an unusual pattern, the possible causes could be:
Alopecia areata – bald patches developing on the scalp, beard and/or eyebrows. Eyelashes may also fall out.
Autoimmune conditions – for example lupus
Burns
Some infectious diseases – for example syphilis
Excessive shampooing and blow drying
Thyroid diseases
Nervous habits, in particular continual hair pulling, scalp rubbing or scratching
Radiation therapy
Tinea capitis – this is ringworm of the scalp
Tumour of the ovary or adrenal glands
Hair loss caused by childbirth or menopause often returns to normal 6 months to 2 years later.
Hair loss caused due to illness, fever, radiation therapy or the use of medication. Once the illness has ended or the therapy has finished, the hair will usually start to grow back.
Hair pieces should never be sutured to your scalp because of the risk of scars, infection and abscess of the scalp.
You should contact your doctor if:
you are losing hair in an unusual pattern
you are losing hair rapidly at a young age, in your teens or twenties
you have any pain or itching with the hair loss
you have acne
the scalp skin is red, scaly or otherwise abnormal
you have bald spots on your beard and/or eyebrows
you have been gaining weight
you have muscle weakness or fatigue
you have intolerance to cold temperatures
In addition for women if:
you have acne, facial hair or an abnormal menstrual cycle