* Sebum (Oil): This is a natural, oily substance produced by the sebaceous glands located within the pores. Sebum helps to moisturize and protect the skin.
* Dead Skin Cells: The skin constantly sheds dead cells, and these can mix with sebum and accumulate within the pores.
* Keratin: This is a protein that is a major component of skin, hair, and nails. Keratin can also build up within the pores.
* Dirt and Debris: Environmental dirt, dust, and pollutants can settle on the skin and enter the pores.
* Cosmetics and Skincare Products: Makeup, sunscreen, and other products can clog pores if not properly removed.
When these substances accumulate and mix together, they can form comedones, which are essentially clogged pores. Comedones can be:
* Blackheads: Open comedones where the mixture has been exposed to air and oxidized, turning dark.
* Whiteheads: Closed comedones where the mixture is trapped beneath a layer of skin.
In some cases, bacteria (especially *Cutibacterium acnes*, formerly *Propionibacterium acnes*) can also be present in the pores, leading to inflammation and the formation of pimples or acne.