Acne that feels deep under the skin is often cystic acne or nodules. These form when pores get blocked far below the surface, trapping oil, dead skin cells, and bacteria in a painful pocket.[1][3][8] Your body fights back with inflammation, making the bump swell and hurt without a visible head.[1][6]
It starts with hair follicles clogging up. Oil called sebum mixes with dead skin and builds up deep inside. Bacteria grow in this mix, and your immune system sends white blood cells to attack, causing redness and tenderness.[1][3][8] Unlike surface pimples, these do not push to the top easily, so they linger and feel like hard lumps.[6]
Hormones play a big role. Androgens, which are male hormones everyone has, boost oil production. Fluctuations during periods, pregnancy, PCOS, or menopause make pores oilier and more prone to deep clogs, especially along the jawline or chin.[2][4][6] Women over 30 often see this pattern from hormonal shifts or birth control changes.[2]
Genetics set the stage. If your family gets cystic acne, you are more likely to as well because of inherited oil gland activity or skin cell shedding habits.[1][5]
Diet can trigger flares. Foods high in dairy, sugar, or glycemic index like sodas, pastries, and whey protein spike insulin and hormones that ramp up oil.[2][5] Stress adds fuel by raising cortisol, which stirs oil glands and worsens inflammation.[1][2][3][6]
Other factors include medications, poor sleep, or friction from masks and helmets that trap sweat and bacteria.[1][3] Overwashing strips the skin barrier, prompting more oil to protect itself.[2]
These deep spots risk scarring if ignored because they damage skin layers over time.[3][8]
Sources:
https://www.fivensondermatology.com/acne
https://www.tuftsmedicine.org/about-us/news/acne-over-30
https://renotahoederm.com/when-its-time-to-see-a-dermatologist-for-acne-in-reno-nv/
https://www.smallbatchserums.com/blogs/blog-post-2/what-causes-cystic-acne-on-the-chin-and-how-to-treat-it
https://www.oreateai.com/blog/what-causes-cystic-acne/4b300784ddb3c5989c18ae6d9d3f32ae
https://www.drbatras.com/skin-diseases/acne/types
https://www.vinmec.com/eng/blog/differentiate-common-pimples-and-skin-cancer-en
https://irvineskin.com/can-cysts-drain-on-their-own/
