Androgenic alopecia: This is the most common form of hair loss and is also referred to as male-pattern or female-pattern baldness. Hormones and genetics seem to play the main role here. Male-pattern baldness is hereditary, from either side of the family, and can even skip generations. It tends to occur on the crown and at the temples and when these patches join together, the top of the hair is left completely bald.  For women, the hair thins initially on the frontal area and the crown and moves down the sides of the he, while the back of the he remains dense with hair. This is hereditary and tends to affect women mostly after menopause.

Toxic alopecia: This type of hair loss seems to occur following physical or emotional stress. Things such as illness, scalp infections, sudden loss of weight, surgery, drugs, and pregnancy/childbirth can cause this type of hair loss.

Alopecia areata: This is actually a skin disorder which causes hair on the affected skin areas to fall out. It is usually the scalp or beard and is thought to have autoimmune causes. This type of hair loss seems to be most common in young people. The hair usually grows back.

Alopecia universalis or totalis: All body hair is lost, from everywhere, including eyebrows and eyelashes. Hair follicles are not destroyed; the inability to grow hair back is psychological and getting hair to grow back again is not easy.

Trichotillomania: This is hair loss due to hair pulling, a habit or condition that can be corrected with treatment.

Scarring alopecia: This is hair loss that occurs at the site of scars or damaged areas such as burns or skin cancer.