Pimples occur mainly due to hormonal imbalances which causes an overproduction of oil and cells inside a skin follicle. They block the opening of the skin pore and cause the follicle under the skin to swell and become red. It usually starts in teenage, but most of the time lasts into adulthood
Next Steps
Severe acne takes time to come uhder control. Also the hormonal imbalances is a major trigger.
Health Tips
Refer What Makes Your Skin Prone to Acne? Top 5 Causes of Acne" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/what-makes-your-skin-prone-to-acne-top-5-causes-of-acne-14523/post
"Teen Acne: What Helps, What Hurts!" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/teen-acne-what-helps-what-hurts-14525/post