Your skin makes oil, called sebum, through small glands under the surface to keep it soft and protected. Sometimes these glands work too hard and create extra oil, leaving your face shiny or greasy.
Sebaceous glands act like tiny factories in your skin. They sit near hair follicles and pump out sebum all day and night. A balanced amount keeps skin healthy, but when they overproduce, oil builds up fast, especially on the forehead, nose, and chin in the T-zone area where glands are more crowded.[1][4][5]
Genes play a big role in this. If your parents have oily skin, you might inherit larger glands or ones that react strongly to signals. These traits show up more in teenage years when hormones kick in.[1][2][3][4]
Hormones are another key trigger. During puberty, monthly cycles, pregnancy, or stress, your body releases chemicals like cortisol that tell glands to make more sebum. Lack of sleep or big life changes can do the same.[1][2][3][6][9]
Weather and surroundings matter too. Hot, humid air makes glands more active, while sweating mixes with oil for a slick layer. Cold, dry spots might make skin crank out extra oil to fight dryness.[1][4][5][6]
What you put on your skin can backfire. Harsh cleansers or ones with alcohol strip away natural oils. Your skin thinks it is under attack and rushes to replace them, often making twice as much.[3][7][8]
Diet and dehydration sneak in as causes. Foods loaded with sugars and fats can rev up glands. If skin lacks water, it pumps out more oil as a shield.[2][7]
Medications or over-scrubbing add to the mix. Rough exfoliation damages the skin barrier, prompting more oil to protect it.[2][3][7][8]
Skin on areas like the nose or even the body has denser glands, so oil shows up quicker there.[2][4]
Sources
https://worldofasaya.com/blogs/skin-types/understanding-oily-skin-genetic-factors-explained
https://www.oreateai.com/blog/understanding-oily-skin-causes-effects-and-solutions-for-oily-butts/01199c75d3445cadc460b7fb5613f5d2
https://www.youtube.com/watch?v=MoyXp1NJKxc
https://www.yoprettyboy.com/blogs/our-thoughts/why-is-my-nose-so-oily
https://www.kins-clinic.com/blogs/understanding-blemish-prone-skin-causes-treatments-prevention
https://dermalogica.com.vn/en/blogs/living-skin/da-do-dau-sau-khi-ngu-day
https://www.youtube.com/watch?v=EkVe0ihUkOY
https://worldofasaya.com/blogs/skin-types/7-reasons-melanin-rich-skin-gets-extra-oily
https://www.aboutskinderm.com/skincare-for-teens-tips-for-managing-acne-and-oily-skin/
