Alopecia
Alopecia is a condition of hair loss on head and body. It has several forms of hair loss and its one form is know as androgenic alopecia or pattern alopecia means baldness. It can be caused by several issues including tight hair styles such as ponytails, braids etc causing traction alopecia. Alopecia areata shows hair loss in patches on head, beard, mustache, eyebrows and other parts of body wherever Alopecia totalis shows more expanded form a complete baldness or head hair loss. Alopecia universalis however causes all body hair to fall out. Alopecia may occur due to iron deficiency, cancer, genetics etc.

Symptoms of alopecia:
Symptoms of alopecia are shown by noticeable hair loss, and skin lesions. Androgenic alopecia which includes male pattern baldness and female pattern baldness shows hair loss on scalp. In male pattern baldness males generally start experiencing hair loss on their head in the form of receding hair line, gradual hair loss from frontal and crown scalp at their early twenties. While in female pattern baldness women often experience thinning of hair on their entire scalp showing most serious hair loss at their crown.

Causes of alopecia:
There are several causes behind alopecia including:

Alopecia mucinosa: Alopecia mucinosa also known as follicular mucinosis, which shows mucin around hair follicles under microscope. It presents bald patches where hair follicles are generally present and affects face, neck and scalp along with any other body part. It was first reported by Pinkus in 1957. Accumulation of mucinous material in damaged follicles creates an inflammatory condition and red plaques on the skin and patchy hair loss.
Androgenic alopecia: Androgenic alopecia also called male pattern baldness and female pattern baldness is a hair loss type that occurs due to androgenic miniaturization. It affects over seventy percent men and forty percent women worldwide.
Chronic inflammation: Chronic inflammation with redness or swelling due to damaged cells, pathogens or irritants etc may cause hair loss.
Diabetes: Both types of diabetes also cause hair loss or thinning of hair on head, face and other body parts.
Fungal infection: Tinea capitis also called Herpes tonsurans /Ringworm of hair or Rignworm on head causes superficial fungal infection to scalp through dermatophytes of Trichophyton and Microsporum genera which attack hair shaft in hair follicles. It shows single or multiple patches of hair loss with inflammation and itching.
Other causes of alopecia include hereditary disorders, Hormonal changes, hyper-vitaminosis of Vitamin A, deficiency of Iron, malnutrition and some medications etc.