What Cuases Acne?

Acne is essentially a small bacterial infection inside your pore. Bacteria gets trapped in an environment with oil and skin cells (that it eats) and rapidly multiplies. The immune response makes the site inflamed and irritated. Your body sends in white blood cells which kill the bacteria, and eventually the spot disappears.  

Heres what Happens:

• extra oil and skin build up in the pore
• bacteria enter the pore and feed off of the oil and skin.
• your immune system reacts and tries to fight the infection.

When treating acne there are four things to target:

1. Oil
2. Dead Skin Cells
3. Inflammation
4. Bacterial growth 

Types of Acne

In acne development, different lesion types represent varying stages of inflammation and severity. Papules are small, raised, red bumps that form when a pore becomes clogged with excess oil, dead skin cells, and bacteria, triggering inflammation but without visible pus. Pustules are similar in size but contain a yellowish or whitish center filled with pus—an accumulation of white blood cells—indicating a more advanced inflammatory stage. Nodules are larger, firm, and painful lumps that form deep under the skin when the infection and inflammation penetrate beyond the hair follicle, often lasting weeks and risking skin damage. Cysts are the most severe form, large, soft, and pus-filled lesions that also develop deep within the skin; they are prone to rupture, can be very painful, and often lead to scarring if untreated. Together, these lesion types reflect the progression from surface inflammation to deep tissue involvement in acne’s lifecycle.

What is Pus?

Pus is a thick fluid made up of dead white blood cells (mostly neutrophils), dead skin cells, bacteria (alive or dead), and tissue debris. It’s essentially the byproduct of your immune system fighting an infection or inflammation—your body sends white blood cells to the site to destroy invading bacteria, and the leftovers collect as pus.

What happens next depends on the severity of the inflammation:

• Small surface infections (like minor pimples or pustules) may naturally dry up as the immune system clears the bacteria. The pus is reabsorbed into the body, the swelling goes down, and the skin heals.
• Larger or deeper infections may rupture on their own, releasing the pus externally.
• Persistent or severe cases (like cystic acne) might need professional drainage or treatment—otherwise the pus can stay trapped, prolonging inflammation and increasing the risk of scarring.

Once the immune system finishes its “cleanup,” the body repairs the tissue, and the pus—along with its contents—either drains away or is broken down and reabsorbed into the lymphatic system.

Whitehead Vs. Blackhead

A whitehead and a blackhead are both types of comedones—clogged pores that form when excess sebum (oil) and dead skin cells block a hair follicle—but they differ in whether the pore remains closed or open.

A whitehead is a closed comedone: the pore is sealed by a thin layer of skin, trapping the clog beneath the surface. This prevents air from reaching the material inside, so it appears white or flesh-colored.

A blackhead is an open comedone: the pore remains open, allowing air to reach the trapped sebum and debris. When exposed to oxygen, the melanin in the debris oxidizes, turning it a dark brown or black color—hence the name.

In short: same clog, different “lid status”—closed pores create whiteheads, open pores create blackheads.