Acne can be caused by hormonal changes that stimulate the sebaceous or oil producing skin glands. Certain changes such as menstrual periods, pregnancy, use of birth control pills, stress, lack of exercise, and bad diet can contribute and aggravate acne. Following are the several most common types of acne.

Papules are inflamed lesions that usually appear as small, pink bumps on the skin and can be tender to the touch.

A Comedone is simply an enlarged hair follicle plugged with oil and bacteria. This lesion is often referred to as a microcomedo because it cannot be seen by the naked eye.

A plugged follicle, or comedo, that stays beneath the skin, is called a closed comedo or whitehead. Whiteheads usually appear on the skin surface as small, whitish bumps.

A comedo that reaches the surface of the skin and opens up is called a blackhead because it looks black on the skin's surface. This black discoloration is due to oxydization of sebaceous substances by oxygen in air and is not due to dirt.

Pustules also known as pimples are inflamed, pus-filled lesions that can be red at the base.

Nodules are large, painful, solid lesions that are lodged deep within the skin.

Cysts are deep, inflamed, pus-filled lesions that can cause pain and scarring.

A Hypertrophic scar is an overgrowth of scar tissue at the site of a skin injury

Depressed scar-is an overgrowth of scar tissue at the site of a skin injury