Skin is the largest organ in your body and the cells are constantly replaced (from the inner parts of the skin to the outer parts). This constant exchange of the dead cells with new ones creates a protective layer on the surface. This layer protects your skin and body from bacteria, viruses, etc. Hair, nails, and glands are a part of the skin. Due to skin's numerous function in excretion, nutrition, regulation of temperature, etc., there are numerous conditions associated with it.

Acne (lat. Acne vulgaris), also known as pimples, are the inflammatory skin condition which is caused by the changes in the pilosebatial unit of the skin. This is a structure in the skin that is made out of hair follicle and its associated sebaceal gland. This gland produces sebum which is a type of oil. This process happens all the time in a person's life, but when there is an excess of sebum and excess in cell reproduction in the skin, and if there is something blocking their passage out of the follicle, blockage will occur. When there is no drainage from the follicle, the bacteria will eventually join in, and this is the main cause how acne develop. This condition usually occurs during puberty. Some studies have shown hormonal imbalances to be linked with acne formation in puberty. When the individual reaches adolescent age, the acne will usually dissapear. This is not a rule, and for some people they stay even longer. Acne affects a large percentage of the population during a lifetime.