A pimple, zit or spot is a kind is the result of excess oil getting trapped in the pores. Some of the varieties are pustules or papules.
Inside the pore are sebaceous glands which produce sebum. When the outer layers of skin shed (as they do continuously), the dead skin cells left behind may become “glued” together by the sebum. This causes a blockage in the pore, especially when the skin becomes thicker at puberty. The sebaceous glands produce more sebum which builds up behind the blockage, and this sebum allows bacteria to grow, including the species Staphylococcus aureus and Propionibacterium acnes, which causes inflammation and infection that leads to the pimple.
Acne, also known as acne vulgaris, is a long-term skin disease that occurs when hair follicles are clogged with dead skin cells and oil from the skin. It is characterized by blackheads or whiteheads, pimples, oily skin, and possible scarring. It primarily affects areas of the skin with a relatively high number of oil glands, including the face, upper part of the chest, and back. The resulting appearance can lead to anxiety, reduced self-esteem and in extreme cases depression.
Genetics is thought to be the primary cause of acne in 80% of cases. The role of diet and cigarette smoking is unclear, and neither cleanliness nor exposure to sunlight appears to play a part. During puberty, in both sexes, acne is often brought on by an increase in hormones such as testosterone. A frequent factor is excessive growth of the bacterium Propionibacterium acnes, which is normally present on the skin.