What Causes Acne?

Jeff Hautala
By Jeff Hautala, Co-Founder of Exposed Skincare

Acne vulgaris is globally one of the most common skin conditions. There are millions of products and as many acne treatments on the market, and the Internet is swamped with so-called health information. This makes finding good advice confusing and frustrating, especially if you’re tired of home remedies that don’t seem to work, or have been using one expensive over-the-counter product after the other with little effect.

In this article, we’ll separate fact from fiction regarding this skin condition, but before we start—don’t rely solely on the Internet for advice, diagnosis, or treatment. This is especially true if you need to treat severe acne. Acne vulgaris is a very multi-faceted skin condition, and there’s no one-size-fits-all in terms of products or acne treatments. Therefore, we suggest you see a dermatologist 👩‍⚕️ or qualified healthcare provider to consider your options.

Finding out what causes acne can help you find the best treatment for your skin.

Different Types of Acne

Knowing what type of acne you have means that you are already halfway towards the solution 📝.

Blackheads and Whiteheads

Blackheads are small, pore-sized dots typically dark brown in color, and whiteheads are small, pore-sized dots that are often skin colored or slightly white.


If you have a white bump with red edges that’s maybe painful to the touch, that is most likely a pimple, sometimes called a papule. Once there is a clearly defined white or yellow head, it’s officially considered a papule.


Cysts are inflamed, but they don’t have a clear head. Instead, they have a blister-like appearance, but with a thicker layer of skin, and are soft to the touch. Cysts and papules are generally seen as more severe acne than blackheads and whiteheads.

What Causes Acne?

When we search for reasons why pimples form in the first place, it comes down to this:

  • inflammation 🔥
  • bacteria 🦠
  • excess oil (sebum) production.

All acne is due to a combination of these three, but each has its own underlying causes with different risk factors.


All acne starts with some degree of inflammation 🔥. The skin can become inflamed due to a host of factors that cause irritation. When the skin around the pores and hair follicles is irritated, it swells slightly, so the openings constrict. This constriction traps excess sebum, dead skin cells, and bacteria, which often lead to the formation of mild to severe acne. The first rule of treating acne should always be to reduce inflammation.

Acne-Causing Bacteria

A specific surface bacteria, P. acnes 🦠, is a natural part of the microbiome always present on the skin. They only become a problem when inflammation traps them in pores or hair follicles. Once trapped, the microbes start to multiply and the body responds defensively and infection results. As if that’s not enough, these P. acnes feed on oil.

Over-active Oil Glands

The skin is never completely oil free, as it needs sebum for its own health and protection. Excess sebum production can happen for any number of reasons, including an inflammatory response due to irritation. When too much oil is produced for whatever reason, it gets backed up in the pores, causing clogs and stimulating infection that leads to acne.

It can be hard to wait for acne to fade, but it does eventually.

Is Acne Contagious?

Acne is not contagious and cannot be passed from person to person simply because P. acnes 🦠 live on everyone’s skin.

However, you can easily spread acne bacteria from one part of your own skin to another by picking at pimples and trying to pop whiteheads or blackheads, or even from bed linen that’s left unchanged for too long.

Stress Acne

Stress acne is a common occurrence largely because our bodies don’t distinguish between emotional and physical threats. All threats are the same to our autonomic nervous systems, the part of our nervous systems responsible for the body’s fight, flight, or freeze response.

With constant or repeated stressors that trigger the fight, flight, or freeze response, our body becomes less sensitive to the hormones that regulate inflammation 🔥 throughout our body, such as cortisol and adrenalin. This dysregulation can lead to increased inflammation, which can kickstart all kinds of acne. Stress can also contribute to hormonal changes that increase the skin’s oil production.

Non-Stress Related Hormonal Acne

Although stress hormones are one of the main culprits for acne, other hormones can be at fault as well. As we delve into some of the external causes of acne, it’s important to remember that all outside causes of acne only produce acne because they affect the three root causes of acne: inflammation, bacteria, and oil production.

Generally speaking, hormonal shifts cause acne because they cause increased oil production, which also encourages accelerated bacterial growth. Menstruation 🩸, polycystic ovarian syndrome, having a baby, taking steroids, and using creatine can all affect hormones in such a way as to cause increased acne. Treatment options include birth control pills 💊, spironolactone, and isotretinoin, but both these have considerable side effects, some long term.

Steroid Acne

If you’ve ever taken steroids, you may have noticed an increase in acne. When you understand how hormones are related to acne, steroid acne makes a lot of sense. The term “steroids” is actually short for “corticosteroids,” a synthetic form of the hormone cortisol. As mentioned in relation to stress acne, cortisol is integral to our body’s stress response, and overexposure to it can lead to dysregulation of the inflammation response, which causes stress acne.

Steroids work in much the same way. Instead of producing extra cortisol due to stress, steroids introduce extra cortisol artificially. This can improve performance in body-building or in treating an injury or infection, but it also reduces the body’s ability to regulate inflammation 🔥, leading to increased acne.

So how can you tell if you have steroid acne? The best clue is to pay attention to when your breakouts start. If you were relatively acne-free before starting steroids, that is a big clue that they play a role in your recent acne. If you had acne before starting steroids, they could still be affecting your skin. There are a few signs to look out for to help identify steroid acne. First, although steroid acne can appear on the face, back, or arms, it is most common on the chest. Second, it can take the form of many different types of acne, from blackheads to cysts, but inflammatory acne like pimples, cysts, or nodules (hard cysts) is typically more common. If you think your steroids could be causing increased acne, speak with your doctor 👨‍⚕️.

So…Does Creatine Cause Acne, Too?

That’s a fair question. If steroids, typically used in body-building 💪, can cause acne, then it’s possible that creatine, also used in body-building, could cause acne, too. However, creatine is actually very different from steroids, and the research on the relationship between creatine and acne is much less clear. It’s important to note that no major research study has directly examined the relationship between creatine and acne. All the information we have on creatine and acne is based on its general properties and how we assume it will interact with acne.

Creatine is a supplement that increases the body’s capacity to store energy, which can boost performance in body-building and sports.

While steroids are an artificial hormone, creatine simply manipulates hormones, rather than mimics them. Some studies have shown that creatine can increase testosterone levels, which can boost oil production and lead to more acne. But creatine isn’t the only way testosterone levels can shift to cause acne.

Does Caffeine Cause Acne?

In many ways, it makes sense that caffeine would increase acne, but there is currently no research to support this. The main reason some dermatologists 👩‍⚕️ suspect caffeine could contribute to acne is because of how it heightens the autonomic nervous system. As we discussed earlier, when the body is stressed, it becomes inflamed, and caffeine makes the body even more sensitive to stress, potentially increasing inflammation 🔥 and therefore acne.

Although this theory makes sense, it’s important to remember that it’s just a theory. There’s no research confirming or denying caffeine’s role in acne formation, so for now at least, there’s no need to cut it out of your diet cold turkey.

Do Eggs Cause Breakouts?

Many people have the same concerns about eggs 🥚 causing acne that they do about dairy causing acne: hormones. It’s important to note that growth hormones have not been proven to increase pimples, but even if they did, you wouldn’t have to worry about it with eating eggs, because chickens 🐔 are normally not given hormones. Generally speaking, we feel confident in saying that eggs do not usually cause acne.

Foods you are sensitive to have the potential to increase acne. It all comes back to inflammation. If you’re slightly allergic to a food, resulting in redness, hives, or any kind of swelling, your pores may constrict and acne could increase.

If you suspect a correlation between eating certain foods and your acne, you don’t need to wait for official research to come out. Do your own. Make everything else about your day as consistent as possible for two weeks and make sure to eat that food every day. Then, eat normally for a week 📅, while keeping all other factors like skin care and stress as stable as possible. Finally, cut out that food entirely for two weeks.

Get specific, count the number and type of acne lesions you have at the beginning and end of each week, and if you find a connection that seems significant, then maybe consider cutting back on that food.

We don’t recommend cutting foods out entirely, and we definitely don’t recommend cutting out entire food groups, like all carbs or all sugars 🍩. These kinds of restrictive diets can cause immense amounts of anxiety and stress, which could actually increase your acne. As with all dietary changes, it’s all about moderation.

The research on dairy and acne is inconclusive now, though further studies are being conducted.

Does Smoking Weed Cause Acne?

As with vaping, not many studies have been conducted on how smoking weed affects acne. Some sources claim that weed itself doesn’t increase acne, but eating a bunch of greasy or sugary foods because of “the munchies” can. As we’ve already intimated, though, the link between acne and diet is tenuous and under-researched.

Limited research has also found that marijuana may increase testosterone and other androgens, which can increase oil production and lead to increased acne.

Still, these are theories based on minimal research, so for now, we can’t say decisively how smoking weed will affect acne.

Does Sweat Cause Pimples?

In short, no. Acne mechanica, typically thought to be due to sport and sweating, is in fact induced by friction, such as tight uniforms or sports equipment that chafe and irritate the skin during exertion. It’s also common among flute and violin players 🎻, and can sometimes appear on the breasts during menstruation when the breasts swell and bras fit more tightly than usual. This friction can irritate the skin, leading to breakouts.

Is It Possible To Get “Pillowcase Acne”?

It’s true, your pillowcase could be contributing to your acne if you aren’t washing it often enough. Oil, bacteria, and dead skin cells can be transferred from your skin to your pillowcase, then when you lay your head back down at night, they can be transferred right back to your skin. To avoid “pillowcase acne,” we recommend washing your sheets 🧼 once a week if possible.

If you have acne, it’s a good idea to wash your pillowcase once a week to prevent a buildup of acne-causing bacteria, oil, and dead skin cells.

Generally, the best way to treat acne is with a gentle skin care routine 🍃, like the Exposed Skin Care routine. Our Basic, Expanded, and Ultimate skin care kits make good, healthy skin care available to everyone, from acne treatment newbies to skin care gurus.

In high concentrations, otherwise helpful chemicals such as benzoyl peroxide and salicylic acid can be too harsh on acne prone skin—even more so if used twice a day. As we now know, this will not reduce inflammation, but increase it, which may cause more breakouts.

Exposed Skincare products contain safe amounts of benzoyl peroxide and salicylic acid that are guaranteed not to cause skin irritation. Our moisturizers are also non-comedogenic, meaning they will nourish the skin without any increased risk of clogging 👍.

At Exposed Skin Care, we offer a wide variety of products to ensure that everyone can benefit from our carefully crafted formulas and gentle products.