Hair is a protein filament that grows from follicles found in the dermis, or skin. Hair is one of the defining characteristics of mammals. Hair loss, also known as alopecia or baldness, refers to a loss of hair from the head or body. Baldness can refer to general hair loss or male pattern hair loss.Hair loss and hypotrichosis have many causes including androgenetic alopecia, fungal infection, trauma (e.g., due to trichotillomania, radiotherapy, chemotherapy, nutritional deficiencies (e.g., iron deficiency) and autoimmune diseases such as alopecia areata. Causes:Male pattern baldness, deficiencies in certain nutrients, infection, drugs, trauma, pregnancy etc.