These are some of the most frequent causes of alopecia totalis or hair loss:

Drugs – Drugs used to treat cancer, blood thinners, antidepressants and high blood pressure medications and pills for birth control and high doses of vitamin A can cause hair loss.

Diet – Too little protein and too little iron in your diet can lead to hair loss.

Stress or illness – you can start to lose hair from one to three months after a stressful situation, such as major surgery. High fever, severe or chronic infections can lead to hair loss.

Birth – You can lose large amounts of hair within two to three months after delivery.

Alopecia areata – a condition in which hair loss occurs only in some areas, resulting in hair loss patches the size of a coin or larger.

Thyroid disease – An overactive or underactive thyroid can cause hair loss or hair

Ringworm – If this fungal infection occurs on the scalp can cause small patches of scaling skin and some hair loss.