The cause of pimples is unknown. The process by which a pimple develops is highly intricate. While we do know that a pore collapses on itself and blocks sebum (skin oil) from escaping, we do not fully understand why this process takes place in one sebaceous gland versus another.
Causes of Acne May Include:
Hormones. Acne is at least in part a hormonal disease. We know this because acne symptoms start only after adequate levels of hormones are present during puberty. Also, we know that acne symptoms usually increase when androgen (male hormone) levels increase. Increased levels of growth hormone and IGF-1 may also affect acne. Exactly how and why hormones affect acne remains unknown. More on hormones »
Diet. We do not know whether diet and acne are related. More research is required before anyone makes definitive claims. However, it is not yet time to discount the effect of diet on acne. More on diet »
Vitamin deficiency. Many of us have inadequate levels of vitamins and minerals in our bodies, especially vitamin D. How and if this affects acne is unknown. More on antioxidants »
Stress. The mind and the body are connected. This is not Eastern philosophy, it is undisputable physical reality. Emotional stress affects our endocrine (hormone) system, digestive system, respiratory system, immune system, and various other bodily systems. Over-taxing the body through an overly demanding exercise schedule or lack of sleep may also cause physical stress, which can adversely affect our bodily processes. We know that both emotional and physical stress can aggravate acne, but exactly why remains a mystery. More on stress »
Evolutionary biology. Acne is a genetic disease. If your parents had acne, chances are you will as well. Why would evolution select for this trait? That is still unknown.
Inflammation. Acne pimples are often characterized by inflammation, which includes redness and soreness. Whether the body’s inflammatory response is a main cause of the acne formation process from the start or enters into the process more strongly once a pore is already clogged is the cause of debate. Most acne medications and treatments, including benzoyl peroxide, isotretinoin, retinoids, dapsone, and zinc have specific anti-inflammatory properties, which are thought to be partly responsible for their anti-acne action. Interestingly, evidence also points toward lower levels of anti-inflammatory antioxidants, such as vitamin A, vitamin E, and selenium, in the skin of people with acne. Furthermore, while results are still far from conclusive, some evidence is pointing toward a potentially beneficial effect from anti-inflammatory low glycemic diets, hinting toward systemic inflammation as a risk factor for acne.
And more... The real explanation could be a complex mix of the above factors, or some yet undiscovered cause may be uncovered. Acne remains one of medical science’s great unsolved mysteries. Why does it come about? Why does it subside in some people and not others? There are certainly many more questions than there are answers. Since we do not know what causes pimples, our time is better spent finding a tested and effective acne treatment.