What Causes Acne?

What Causes Acne Breakouts in Adults?

Acne is a common skin condition that affects most of us at some point in our lives. While most acne sufferers are teenagers, people of all ages can develop acne.

The biggest myth about acne is that it is caused by poor hygiene or a bad diet. While both poor hygiene and not eating right can contribute to acne, they are not directly related to the root problem that causes acne.

Acne shows up when the body produces too much oil. This oil comes from oil glands in the skin. This oil is meant to lubricate the skin, but when it is overproduced, it gets trapped in blocked oil ducts and other skin features and causes pimples, zits, blackheads, and the other skin problems that we recognize as acne. In severe cases, deep lesions in the skin can develop due to this overproduction of oil–these lesions are called cysts.

Acne Facts

There’s good news for acne sufferers–for most people, acne only lasts between three and four years. Only about 15% of acne cases will last for more than eight years, and these are the most severe cases only.

What Causes Acne?

A small percentage of people will experience acne beyond age 25–about 5% of acne sufferers–and for these people, acne can continue up until age 40 or more.

It may seem like teenage boys have more acne than girls, but this isn’t totally accurate. The difference between acne experienced by men and that experienced by women is that acne in women usually shows up later, as late as age 25. It is true, however, that the most severe cases of acne tend to happen in men, because they produce more male hormones that can contribute to the development of acne.

Women who have acne may notice their acne flares up during their period. About 70% of female acne comes during her period, doctors think this is due to an increase in a hormone called “androgen” that floods the female body just prior to her period. Women who experience acne flare-ups during their period, or women who have a lot of body hair or severely irregular periods, are at increased risk for acne. If this is the case for you, you should speak to your doctor about having your hormone levels checked.

Acne Causes

No matter what you’ve heard about acne being caused by chocolate or exercise, there are only four major factors responsible for causing acne. These four factors work together to cause the typical acne features–the large number of pimples, whiteheads, and blackheads that we call “acne.”

Overactive Oil Glands

The body’s oil glands are located deep within the skin. Also known as “sebaceous glands”, these glands are each connected to a tiny canal in the skin that contains a hair. That canal (with its hair intact) is what we call a “follicle.”

The sebaceous glands produce oil (called “sebum”) that flows up to the skin’s surface through these follicles to lubricate the hair follicles and the skin surrounding them. This is how our skin stays moist and flexible.

These oil glands vary in size, with larger follicles more visible than smaller ones. These large follicles are sometimes called “skin pores, especially in the cosmetic industry. Having “large pores” is a beauty no-no. The body’s oil glands respond to your body’s hormones, producing different amounts of skin oil depending on the hormonal message.

So what can cause these glands to over-produce oil? Stress leads to a flood of hormones in the body that enlarge the oil glands even more. Puberty is another trigger, when the same hormones start to flow throughout the body, causing an increase in oil and growth in follicles.

Blockage of the Skin Pores

The first thing you’ll notice if your body is producing too much oil is “oily skin.” This happens when an overactive oil gland overproduces oil. When some of these pores are blocked, due to producing too much oil, the oil they do produce is literally trapped within your skin’s pores.

How did they get blocked in the first place? Skin pores get blocked by dead skin cells that have bunched together. Unfortunately, the root cause for this clogged pore problem is not known, but doctors tell us that no amount of washing or hygiene can prevent it from happening.

Incidentally, this blockage is what causes pesky blackheads and whiteheads.

Normal Skin Bacteria Activity

Bacteria play a major part in making acne symptoms worse, though bacteria don’t technically “cause” acne.

We know the name of the normal skin bacteria that leads to acne–it is called Propionibacterium acnes, or P. acnes for short. This bacteria is good–a normal part of healthy skin. This bacteria actually protects your skin from invasion by bad bacteria.

Unfortunately, P. acnes can do “too good” of a job. When skin oil gets trapped in a hair follicle, the good bacteria P. acnes begins to grow in the blocked pore. Unfortunately, they don’t mix well–P. acnes produces a chemical that changes the makeup of our skin oil, causing inflammation and irritation.

We need P. acnes, but unfortunately for acne sufferers, sometimes it does its job too well.


Inflamed skin looks swollen, red, hot, and uncomfortable. We can all recognize inflamed skin from across the room, and we certainly know what it feels like to have it on our face. Why does this inflammation of the skin happen?

The body’s immune system is reacting to the presence of irritating oils caused by P. acnes interacting with blocked skin pores. Basically, your body sees the trapped oil and bacteria as a foreign invader and attempts to rid itself of this attack with inflammation.

Acne is a complex process, requiring lots of things to go wrong all at the same time. When these four factors combine, blocked skin pores bulge outward to form the various features of acne.

If you have a problem with acne and can’t control it with over-the-counter products, you should make an appointment with your doctor or get a referral to a dermatologist.

See also:

  1. What Causes Cold Sores?
  2. What Causes Breast Cancer?
  3. What Causes Bed Bugs?
  4. What Causes Bad Breath?
  5. What Causes Overactive Bladder?
  6. What Causes Constipation?
  7. What Causes Hangovers?