What Are the Causes of Acne? 4 Reasons for Pimples on Face

We have already seen what acne is in a previous blog. Now let’s take a look at what causes acne so you can try and prevent it! 

Excess Oil Production – The Main Trigger

Your skin naturally produces sebum (oil) to keep it hydrated and protected. However, in acne-prone skin, oil production is often excessive and plays a major role in breakouts. When too much oil is produced, it mixes with dead skin cells and clogs pores. This creates the perfect environment for acne-causing bacteria, leading to inflammation, pimples, and other types of breakouts.

Interestingly, research has found that it’s not just the amount of oil that matters but also its composition. Studies suggest that people prone to acne tend to have thicker, stickier sebum compared to those who don’t get acne. This altered consistency makes it easier for sebum to trap dead skin and bacteria inside pores, increasing the risk of clogged pores and breakouts.

So why does excess oil production happen? There are several factors can lead to it:

Hormonal Changes (Puberty, Pregnancy, Periods, PCOS)

Hormones play a huge role in controlling oil production. Androgens—male hormones like testosterone—stimulate the sebaceous glands, causing them to produce more oil. This is why:

• Many teenagers experience acne during puberty when androgen levels spike.
• Pregnant women may notice increased breakouts due to hormonal fluctuations.
• Breakouts around the chin and cheekbones are common in women due to hormonal shifts during menstrual cycles.
• People with PCOS (Polycystic Ovary Syndrome) often experience persistent acne due to chronically high androgen levels.

Genetics

Your genes also influence how much oil your skin produces, how thick your sebum is, and how your skin sheds dead cells. If your parents had acne, there’s a higher chance you’ll experience it too. Some genetic factors that contribute to acne include:

• Naturally overactive sebaceous glands.
• A tendency for sebum to be thicker and more prone to clogging pores.
• An impaired ability to shed dead skin cells properly.

Other Factors That Can Increase Oil Production

• Using heavy, pore-clogging skincare or makeup – Some products form a barrier over the skin that traps oil, leading to breakouts.
• High humidity or excessive sweating – Warm, humid conditions cause the skin to produce more oil. If sweat mixes with oil and dirt, it can clog pores, especially in areas like the forehead and cheeks.
• Using overly stripping skincare – Harsh cleansers, strong alcohol-based toners, and excessive exfoliation can strip away too much oil, leaving the skin dehydrated. When this happens, your skin tries to overcompensate by producing even more oil, making breakouts worse.

If you have oily skin, you might notice that breakouts are more common in oilier areas of your face, such as the T-zone (forehead, nose, and chin), where sebaceous glands are most active.

Clogged Pores & Dead Skin Buildup

While excess oil plays a major role in acne, it takes more than just oil to cause breakouts. Another crucial factor is improper shedding of dead skin cells.

Your skin constantly renews itself by shedding dead cells from the surface. In normal skin, these cells fall off naturally. But in acne-prone skin, this shedding process doesn’t happen properly. Instead of flaking away smoothly, dead skin cells stick together and mix with oil, leading to clogged pores. 

Depending on how deep the blockage is, clogged pores can take the form of whiteheads and blackheads, or deeper, red, inflamed pimples, which include papules, pustules and cysts.

Several factors can make your skin more prone to clogged pores and dead skin buildup. These include:

• Not cleansing properly – Dirt, sweat, and oil can accumulate and block pores if not washed away.
• Skipping exfoliation – Regular exfoliation helps remove dead skin, preventing it from building up inside pores.
• Wearing heavy, occlusive products – Some skincare or makeup products can trap oil and debris, leading to congestion.

By managing oil production and ensuring proper skin cell turnover, you can reduce the likelihood of clogged pores and breakouts.

Bacteria & Inflammation – Why Acne Gets Worse

When a pore becomes clogged, it creates an oxygen-poor environment where Cutibacterium acnes (C. acnes), a type of bacteria naturally present on the skin, can thrive. 

While this bacteria is normally harmless, in acne-prone skin, it multiplies rapidly inside clogged pores and triggers the body's immune response, leading to redness, swelling, and inflammation. This is why a small, clogged pore can turn into an angry, red pimple.

Certain habits can spread bacteria and make breakouts worse. These include:

• Touching your face frequently – Your hands pick up bacteria and dirt from surfaces throughout the day. When you touch your face, you transfer these germs to your skin, increasing the risk of infections.
• Not cleaning pillowcases and phone screens – Pillowcases collect oil, sweat, and bacteria from your skin and hair, which can clog pores overnight. Phone screens pick up bacteria from your hands and pockets, and when pressed against your cheek, they can introduce more bacteria to your skin.
• Using dirty makeup brushes and sponges – Makeup tools can harbor bacteria and dead skin cells, which can transfer back to your face and contribute to breakouts.

By keeping your hands, phone, and pillowcases clean, you can reduce bacterial exposure and help prevent acne from getting worse.

Diet & Lifestyle

While acne is not directly caused by diet, research suggests that certain foods may trigger or worsen breakouts in people who are acne-prone. This is because some foods can cause spikes in blood sugar, increase hormonal fluctuations, or promote inflammation, all of which contribute to acne. These include:

• High glycemic index (GI) foods – These cause rapid spikes in blood sugar and insulin, which increases oil production and leads to inflammation. High GI foods include:
• Sugary snacks and drinks (soda, candy, pastries)
• White bread, white rice, and processed cereals
• Fast food and fried foods
• Dairy products – Some studies suggest that milk, particularly skim milk, may contribute to acne. This could be due to hormones and bioactive molecules present in dairy that may influence oil production and inflammation. However, not everyone reacts to dairy the same way.
• Processed and fast food – Diets high in refined carbohydrates, unhealthy fats, and additives may contribute to acne by increasing inflammation and altering hormone levels.

Lifestyle factors can also contribute to acne, including high levels of stress and lack of sleep. 

Stress increases cortisol (the stress hormone), which can stimulate oil glands and make acne worse. This is why people often break out before exams, during work deadlines, or in other high-stress situations.

Poor sleep, on the other hand, can disrupt hormonal balance and weaken the skin’s ability to heal, making breakouts last longer.

Conclusion

Acne is caused by a mix of oil production, clogged pores, bacteria, and hormones. Diet and lifestyle also play a role in triggering or worsening breakouts. Hopefully, after reading this blog, you will have a clear understanding of the causes of acne. Here's some right steps to prevent and manage breakouts.