What Is an Abscess?

An abscess is a pus-filled bump or pocket that forms in or on your body due to an infection. Bacterial infections are the most common cause of abscesses, though an abscess can also form due to a viral, fungal, or parasitic infection.

Abscesses can develop in any part of the body, including the skin, the teeth or gums, or inside the body near internal organs. When an abscess is on or under the skin, your skin may appear red and swollen, feel warm to the touch, and cause pain. Abscesses inside the body cannot be seen but may cause symptoms such as fever, discomfort, and loss of appetite.

Types of Abscesses

An abscess is a collection of pus that is surrounded by swollen, inflamed tissue. When you have an infection, the immune system sends white blood cells to the affected area. As a result, pus—a thick, yellowish fluid made up of dead white blood cells, bacteria, and tissue—accumulates at the site of infection and causes the formation of an abscess.

Abscesses can form anywhere in the body. The most common types of abscesses include:

• Skin abscess: Forms beneath the skin, usually in response to bacteria entering the body through an open wound on the skin, such as a cut, scrape, or insect bite. Skin abscesses can occur anywhere on the body, but most commonly develop on the groin, buttocks, armpit, and legs.
• Tooth abscess: Develops in the teeth, gums, or surrounding mouth tissues. A bacterial infection causes tooth abscesses due to tooth decay, a cracked tooth, or gum disease.
• Internal abscess: Grows on or near your body’s internal organs, such as the lungs, liver, brain, or kidneys. Certain health conditions, such as appendicitis or diverticulitis, can cause an internal abscess.
  

Symptoms

Abscess symptoms vary depending on the cause and location of the abscess. Here's what you can expect depending on the type of abscess you have.

Skin Abscess Symptoms

A skin abscess is typically visible on your skin and may appear pimple-like, but is generally larger and deeper within the skin. Common skin abscess symptoms include:

• A swollen, red, round, and squishy bump on the skin 
• Warm to the touch 
• Painful or tender
  

As a skin abscess progresses, it may become larger and more sore. The skin over the abscess may feel tight and stretched due to pressure from the buildup of pus beneath the skin.

Tooth Abscess Symptoms

A tooth abscess can be painful and causes aching in the bone near the infected tooth. Symptoms of a tooth abscess can include:

• Toothache or throbbing pain around the affected tooth or in the jaw  
• Swelling and redness of the gums
• Sensitivity to hot or cold foods and beverages
• Facial swelling, especially around the affected tooth
• Foul taste or odor in the mouth 
• Difficulty chewing or opening the mouth 
  

Internal Abscess Symptoms

Internal abscess symptoms vary, depending on which organ you are experiencing an infection in. Most internal abscesses can cause symptoms such as:

• Fever 
• Persistent pain in the affected area (e.g., abdominal pain) 
• Nausea
• Vomiting 
• Fatigue 
• Malaise 
• Loss of appetite 
• Weight loss 
• Abdominal or pelvic swelling (abdominal or pelvic abscess)
• Difficulty breathing (lung abscess)

Causes

Bacterial infections are the leading cause of abscesses. But the exact cause of your symptoms will depend on the type of infection you have and where your abscess develops.

Skin Abscess Causes

A skin abscess occurs due to a bacterial infection—most commonly the Staphylococcus aureus bacteria. Normally these bacteria live on the skin without causing harm. If the bacteria enter the body through an open wound, such as an insect bite or cut, an infection can develop and lead to an abscess. Other potential causes of a skin abscess include:

• Blocked sweat ducts, oil glands, or hair follicles 
• Foreign objects, such as a splinter or debris under the skin 
  

Some risk factors can also increase your chances of developing a skin abscess, including:

• Obesity
• Smoking
• Diabetes
• Intravenous drug use
• A weakened immune system (or, being immunocompromised)

Tooth Abscess Causes

A tooth abscess occurs when bacteria enter the tooth pulp (or, live tissue inside the tooth) and cause the infection. Common causes of a tooth abscess include:

• Tooth decay
• Gum disease
• A cracked tooth 
  

The immune system sends white blood cells to eliminate the bacteria, leading to the buildup of pus at the root tip of the affected tooth. While anyone can develop a tooth abscess, certain factors can increase your risk, including:

• Poor oral hygiene 
• Cavities 
• Impacted or overcrowded teeth 

Internal Abscess Causes 

Internal abscesses can occur if bacteria or other infection enters the body. You might be at risk of developing an abscess if you have any of the following health conditions:

• Trauma (e.g., surgery, injury) 
• Appendicitis 
• Diverticulitis
• Crohn’s disease
• Pancreatitis
• Pelvic inflammatory disease 
• Pneumonia
  

Other factors that can raise your chances of an abscess include:

• Perforated ulcer disease 
• Recent surgery 
• A weakened immune system 

Diagnosis

The type of abscess you have will determine how you receive a diagnosis. While a primary care physician or dermatologist (a doctor who specializes in the skin) can diagnose skin and internal abscesses, a dentist will likely diagnose a tooth abscess.

Your healthcare provider will first ask about your symptoms and medical history, including whether you’ve had recent injuries, infections, or surgeries. They will also perform a physical examination to check for signs of an abscess before giving you an official diagnosis.

Here's what to expect during the diagnostic process for each type of abscess:

Treatment

In order to make the abscess go away, you have to drain the pus from the abscess. Keep in mind: most abscesses do not go away on their own and require medical treatment to drain and clear the infection. Without treatment, an abscess can persist, worsen, or potentially spread to other areas of the body. Your exact treatment plan will depend on the type of abscess you have.

Skin Abscess Treatment 

In a few cases, you may be able to drain a very small abscess by applying a warm compress to the area a few times daily. To do this:

• Wash your hands thoroughly 
• Place a warm, wet washcloth on the abscess for several minutes at a time
• Remove the washcloth and gently pat the skin dry 
• Do not attempt to pop or squeeze the abscess with your hands or household items, as this can worsen the infection or increase the risk of spreading it to other areas on your body

If you have a bigger abscess, it's best to see a healthcare provider. Depending on their recommendation, your provider may suggest:

• Incision and drainage: A healthcare provider will make a small incision (cut) in the abscess to allow the pus to drain out. After drainage, they will clean the wound and wrap the skin with gauze. The gauze allows the pus to continue draining and prevents other bacteria from entering the wound.
• Antibiotics: Sometimes, prescription antibiotics can help clear the infection and prevent the abscess from forming again.
  

Dental Abscess Treatment

Treatment for a tooth abscess tends to vary depending on the severity of the infection. Treatment options may include:

• Root canal: A dentist or endodontist (a dentist that specializes in tooth pain and pulp) will remove bacteria from the empty root canals in your tooth, clean and fill the canals, and seal the space to prevent the infection from returning. After treatment, your dentist will place a crown on the tooth to protect it and restore its function. 
• Antibiotics: Destroys the bacteria and clears the infection from your mouth.
• Tooth extraction: In severe cases, your dental care provider may pull out the tooth to drain the abscess and clear the infection fully.

Internal Abscess Treatment

Internal abscesses require medical treatment to drain the pus and eliminate the infection. Depending on the location of the abscess, healthcare providers use one of the following methods to drain the abscess: 

• Needle aspiration: Involves using a needle and catheter to withdraw and drain the pus. Imaging techniques, like an ultrasound or CT scan, help guide the insertion of a needle and catheter into the affected area to drain the abscess. Once the needle accesses the abscess, your provider will remove the needle and leave the catheter in for several days to ensure the pus fully drains.
• Surgical drainage: In the chance that your healthcare provider can't safely treat the abscess with needle aspiration, you may require surgery. However, the exact surgical procedure you receive will depend on where your abscess is located.
• Antibiotics: After a provider drains the abscess, antibiotics can help prevent the infection from spreading or returning. A sample of the drained pus is usually sent to the lab to determine which bacteria is causing the infection, which helps healthcare providers choose the most effective antibiotic to prescribe to you.

When To See a Healthcare Provider

If you have signs and symptoms of an abscess, see a healthcare provider for diagnosis and treatment. Seek immediate medical attention if you experience any of the following situations:

• The abscess becomes larger or more painful or the surrounding area becomes more swollen and red
• Red streaks on the skin near the abscess 
• Fever or chills 
• Symptoms suddenly worsen or you feel extremely fatigued
• You have a history of abscesses or a recent abscess has returned 
  

A Quick Review

An abscess is a collection of pus, usually caused by a bacterial infection. Abscesses can develop anywhere in the body, including the skin, mouth, and internal organs. Signs and symptoms of an abscess vary, depending on the body part affected. A skin abscess may appear like a pimple and cause pain and tenderness. A dental abscess may feel like a toothache. Internal abscesses can cause fever, malaise, fatigue, and loss of appetite.

Most abscesses require medical attention and treatment, as they typically do not resolve on their own. Treatment options may include incision and drainage, antibiotics, or surgical intervention in some cases.