An abscess forms when the body’s immune system walls off an infection, creating a pocket of pus deep inside tissue. You get an abscess when bacteria get past your skin or another barrier and your immune system responds by sending white blood cells to fight them. That battle creates pus — a mix of dead tissue, bacteria, and immune cells — and the body builds a wall around it to keep the infection from spreading. This can happen almost anywhere: under the skin, in a tooth, in a hair follicle, or inside an organ.
How Do You Get An Abscess?
Bacteria are the direct cause. The most common culprit is Staphylococcus aureus, a bacterium that lives on the skin of roughly one in three people without causing harm. When it enters through a break in the skin, it can multiply and trigger an abscess.
But bacteria need an opening. That opening comes from somewhere. Understanding those entry points is the most practical way to understand how abscesses happen.
Common routes include:
- Hair follicles. A blocked or irritated follicle can become a small abscess. This is what a boil is.
- Minor cuts and scrapes. Even tiny breaks in the skin let bacteria in.
- Puncture wounds. A nail, splinter, or animal bite pushes bacteria below the surface where the immune system struggles to clear it.
- Blocked glands or ducts. Sweat glands, oil glands, and ducts can clog and become infected.
- Foreign objects. A splinter left in the skin creates a persistent pocket where bacteria thrive.
- Spread from nearby infection. A tooth infection can spread into the jaw. A skin infection can spread into deeper tissue.
Once bacteria are inside, the immune system responds. Neutrophils — a type of white blood cell — rush to the site and attack the bacteria. The byproduct of that fight is pus. The body then forms a fibrous wall around the area, isolating the infection. This wall is what makes an abscess different from a simple infection. It also makes an abscess hard for the immune system to clear on its own, because antibiotics and immune cells have trouble penetrating the wall.
What Increases Your Risk of an Abscess?
Anyone can get an abscess. But certain conditions make it more likely. These risk factors are well established in clinical literature.
Weakened immune function is the biggest one. This includes people with diabetes, HIV, or those taking immunosuppressant medications. A weakened immune response means bacteria can multiply before the body contains them.
Poor circulation also plays a role. Blood delivers immune cells to the site of infection. When circulation is impaired — as in diabetes or peripheral artery disease — that delivery is slower.
Skin conditions that cause breaks or inflammation raise risk. Eczema, psoriasis, and even chronic scratching can open the door for bacteria.
Obesity is associated with higher rates of skin abscesses. The reasons are not fully understood, but skin folds, friction, and changes in immune signaling likely contribute.
Intravenous drug use carries a very high risk. Injecting introduces bacteria directly into the bloodstream and under the skin. Abscesses at injection sites are common.
Poor dental hygiene leads to tooth abscesses. Untreated cavities and gum disease let bacteria reach the pulp of the tooth, where they cause infection and pus buildup.
Some risk factors are not modifiable. Others are. But having a risk factor does not mean you will get an abscess. It means the odds are higher.
What Are the Signs and Symptoms of an Abscess?
The signs depend on where the abscess is. A skin abscess is usually obvious. An internal abscess is not.
Skin abscesses typically present as:
- A painful, swollen lump under the skin
- Warmth and redness around the area
- Tenderness to touch
- Pus visible at the surface or draining
- Fever or chills if the infection is spreading
Internal abscesses — in the liver, brain, lung, or abdomen — may cause fever, pain in the affected area, fatigue, and a general feeling of being unwell. These are harder to detect and often require imaging to diagnose.
Tooth abscesses cause throbbing pain, sensitivity to hot or cold, swelling in the jaw or cheek, and sometimes a bad taste in the mouth.
One thing to watch for: a skin abscess that is red, hot, and spreading. That can signal cellulitis or a deeper infection. Fever with an abscess is also a warning sign.
How Is an Abscess Treated?
Incision and drainage is the primary treatment for most abscesses. A clinician makes a small cut and lets the pus out. This is not just a comfort measure — it is often the only thing that works. Antibiotics alone frequently fail because they cannot penetrate the wall of the abscess.
After drainage, the wound may be packed with gauze to keep it open and allow continued drainage. It heals from the inside out. Some clinicians prescribe antibiotics after drainage, especially if there is spreading infection, fever, or a weakened immune system. But for a simple, small skin abscess in a healthy person, drainage alone is often sufficient.
For internal abscesses, treatment depends on location and size. Drainage may be done with a needle guided by imaging. Surgery may be needed for larger or deeper abscesses. Antibiotics are almost always used for internal abscesses.
Do not try to drain an abscess at home. Squeezing or cutting can push bacteria deeper, spread the infection, or cause scarring. This is one of those situations where the instinct to “pop it” is genuinely dangerous.
Can You Prevent an Abscess?
You cannot prevent every abscess. But you can reduce the risk.
Clean minor wounds promptly. Wash with soap and water, apply an antibiotic ointment if you choose, and cover with a bandage. Keep the area clean until it heals.
Do not share personal items like towels, razors, or athletic equipment. Staph bacteria spread easily through skin contact and shared items.
Wash your hands regularly. This is basic but effective. Many skin infections start when bacteria from your hands get into a small break in the skin.
Manage chronic conditions. If you have diabetes, keeping blood sugar in a healthy range supports immune function and circulation. If you have a skin condition, treating it reduces breaks in the skin.
Practice good dental care. Brush, floss, and see a dentist regularly. Tooth abscesses are largely preventable with routine care.
Avoid injecting drugs. If you do, seek help. This is the single highest-risk behavior for abscess formation.
Some people are prone to recurrent abscesses. If you get them often, talk to a doctor. There may be an underlying condition — like diabetes or an immune disorder — that needs attention.
When Should You See a Doctor?
See a doctor if an abscess is larger than a small pimple, is painful, or is not improving after a few days. Also see a doctor if you have fever, chills, or redness that is spreading.
Go to urgent care or the emergency room if:
- The abscess is on your face, neck, or spine
- You have a high fever or chills
- The area is red, hot, and expanding quickly
- You have diabetes, a weakened immune system, or poor circulation
- The abscess is deep or you cannot see the bottom of it
These signs suggest the infection may be spreading beyond the abscess wall. That is a medical emergency.
For tooth abscesses, see a dentist promptly. A tooth abscess will not heal on its own. It can spread to the jaw, sinuses, or bloodstream if untreated.
What Happens If an Abscess Is Left Untreated?
An untreated abscess can rupture. Sometimes that releases the pus and the body clears the infection. But often it spreads. Bacteria can enter the bloodstream — a condition called sepsis — which is life-threatening.
An untreated abscess can also damage surrounding tissue. A tooth abscess can destroy the tooth and infect the jaw. A skin abscess can burrow deeper into muscle or fascia. An internal abscess can damage the organ it is in.
The wall of an abscess is both a containment strategy and a barrier. It keeps the infection from spreading quickly, but it also prevents the immune system from finishing the job. That is why drainage is almost always necessary. The body built the wall; a clinician has to open it.
Abscesses are common. They are also treatable. The key is recognizing them early and getting proper care. Do not wait and hope it goes away.
Frequently Asked Questions
How do you get an abscess?
You get an abscess when bacteria enter through a break in the skin, a blocked gland, or a puncture wound and the immune system responds by walling off the infection. The most common bacterium involved is Staphylococcus aureus, which lives on the skin of many healthy people.
Can an abscess go away on its own?
Small abscesses sometimes drain and heal without treatment, but most do not. An abscess has a wall that prevents antibiotics and immune cells from reaching the infection, so medical drainage is usually needed.
What happens if you pop an abscess?
Popping or squeezing an abscess can push bacteria deeper into tissue, spread the infection, and cause scarring. It can also lead to a more serious infection like cellulitis or sepsis, so it should be drained by a medical professional.
Are abscesses contagious?
The bacteria that cause abscesses, especially Staph, can spread from person to person through skin contact or shared items. The abscess itself is not contagious, but the bacteria that caused it can be passed to others.
