Hair loss, also known as alopecia or baldness, is a loss of hair from parts of the head or the body. In most cases, at least the head is involved. Hair loss can affect one’s scalp or the entire body depending upon the severity. Most people normally shed 50 to 100 hairs in a day which does not cause thinning of scalp hair or balding because new hair replaces shedding hair. Hair loss occurs when this process of hair growth and shedding is disrupted or when the hair follicle after being destroyed is replaced by scar tissue. Hair loss may affect anyone- men, women or children. It can be caused by hormonal changes, medical conditions, ageing process or it may be hereditary in nature. Hair loss in most case may be emotionally traumatic. Most Common types of hair loss include: 1. Male-pattern hair loss,2. Female-pattern hair loss, 3. Alopecia areata, and 4. Thinning of hair, technically known as telogen effluvium.Male pattern hair loss may include a receding hairline that produces an “M” shape or thinning hair at the crown.It may be caused due to genetic factors, male hormones or due to medical conditions.Female pattern hair loss may include overall thinning of the scalp hair or a widening of the part. Hair loss in women most frequently occurs on the top of the head. Over time, as hair loss progresses there is an increased scalp exposure.Alopecia areata is an autoimmune condition where the immune system incorrectly attacks the hair follicle. The affected follicle eventually stops growing visible hair, resulting in circular patches of hair loss across the scalp. Telogen effluvium occurs when hair follicles are prematurely pushed into the telogen or resting phase of hair growth. This condition may occur due to physical trauma, surgery, major illness or during pregnancy.Hair loss without inflammation or scarring may occur due to certain medications including chemotherapy, HIV/AIDS, hypothyroidism, and malnutrition including iron deficiency while hair loss with scarring or inflammation may be due to fungal infection, lupus erythematosus, radiation therapy, and sarcoidosis.