What Causes Acne?


Let’s start with the basics. Contrary to popular legend, French fries and chocolate don’t cause acne. If your vices aren’t the problem, then what causes acne?

An acne blemish begins approximately 2-3 weeks before it appears on your skin’s surface. So while it may seem like you get a pimple overnight, what you’re actually seeing is the final stage of a much longer process. It starts in your sebaceous hair follicles – the tiny holes you know as pores. Deep within each follicle, your sebaceous glands are working to produce sebum, the oil that keeps your skin moist and pliable. As your skin renews itself, the old cells die, mix with your skin’s natural oils, and are sloughed off. Under normal circumstances, these cells are shed gradually, making room for fresh new skin.

But this sloughing process is different for everyone. You might shed cells evenly – or not. Uneven shedding causes dead cells to become sticky, clumping together to form a plug – much like a cork in a bottle. This plug, or comedo, traps oil and bacteria inside the follicle.

The plugged follicle begins to swell as your skin continues its normal oil production. Your body then attacks the bacteria with a swarm of white blood cells. The whole process takes 2-3 weeks, culminating in the dreaded pimple.

Here are some of the main culprits known to cause acne:

Culprit #1: Hormones.

For the majority of acne sufferers, the trouble begins at puberty, when the body begins to produce hormones called androgens. These hormones cause your sebaceous glands to enlarge, which is a natural part of the body’s development. However, as an acne sufferer your sebaceous glands are over-stimulated by androgens, and this can continue for decades. Androgens are also responsible for acne flare-ups associated with the menstrual cycle and, on occasion, pregnancy.

Culprit #2: Extra sebum.

When the sebaceous gland is stimulated by androgens, it produces extra sebum. In its journey up the follicle toward the surface, the sebum mixes with common skin bacteria and dead skin cells that have been shed from the lining of the follicle. While this process is normal, the presence of extra sebum in the follicle increases the chances of clogging – and can cause acne.

Culprit #3: Follicle fallout.

Normally, dead cells within the follicle shed gradually and are expelled onto the skin’s surface. But if you’ve got overactive sebaceous glands these cells shed more rapidly. Mixed with a surplus of sebum, the dead skin cells form a plug in the follicle, preventing your skin from finishing its natural process of renewal. While not acne itself, this plug encourages the growth of acne bacteria.

Culprit #4: Bacteria.

The bacterium Propionibacterium acnes (P. acnes for short) is a regular resident of all skin types. It’s part of your skin’s natural sebum maintenance system. Once a follicle is plugged, however, P. acnes bacteria multiply rapidly, creating the chemical reaction we know as inflammation (see video) in the follicle and surrounding skin.

Culprit #5: Inflammation.

When your body encounters unwanted bacteria, it sends an army of white blood cells to attack the intruders. This process is called chemotaxis or, simply put, the inflammatory response. This is what causes your pimples to become red, swollen and painful. The inflammatory response is different for everyone, but studies have shown that it is especially strong in adult women. That is why many women continue to suffer from acne well after their teen years. It’s definitely not the chocolate.