Pimples occur when oil becomes trapped under the skin. According to Medical News Today, the oil glands are connected to the skin pores via hair follicles. The glands create a liquid called sebum, which is responsible for pushing dead skin cells to the surface. Excess sebum and dead skin cells can cause an infected plug underneath the skin that creates a pimple as it breaks down.
Pimples are also referred to as acne. According to Medical News Today, there are six different types of pimples that can occur in both adolescents and adults. Whiteheads are small in size and remain underneath the skin. Blackheads present as black dots on the skin's surface and resemble dirt. Pustules appear on the skin's surface and consist of a red base. There is typically visible pus at the top of the pustule. Nobules are painful solid pimples with no visible pus. Cysts are painful cystic pimples on the skin's surface that are filled with pus.
According to WebMD, popping and picking at pimples is a common mistake made by many acne sufferers. It is never a good idea to attempt to pop or pick at a pimple, as picking the skin can lead to scarring and popping the pimple can cause the pus and bacteria to push deeper into the skin, leading to additional swelling and irritation.