Causes, Symptoms, and Treatment of Skin Boils

Skin boils look like large pimples. They can sometimes be mistaken for spider bites.

Boils are also called furuncles or carbuncles. They are usually caused by bacteria. Some, though, can be caused by fungi.

Boils appear as a red to purple lump on the skin with a white head. The head contains a white-yellow pus.

Boils are relatively common and can heal within two weeks with proper care. Treatment is typically done at home. You may need to see your healthcare provider, though, if the boils are very bad or get worse.

This article will discuss some of the common causes and symptoms of skin boils. It will also provide information on how to treat a skin boil and when you should call a healthcare provider.

Causes of Skin Boils

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Skin boil
Skin boil.

Getty Images 

Skin boils are usually caused by a bacterial infection. The most common boil-causing bacteria are Staphylococcus aureus, also known as staph, and group A Streptococcus. Both of these infections can be treated with antibiotics if they become serious.

Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph that is resistant to common antibiotics. MRSA infections are harder to treat, but they look similar to those caused by other forms of staph.

Boils form when normal bacteria on the surface of the skin invade hair follicles. These are stocking-shaped structures in the skin that produce hairs. The infection often includes a group of follicles.

When the follicles are damaged, the bacteria can grow into the nearby tissue. Sometimes the infection can spread into the bloodstream. This is rare, but when it happens it can cause a serious illness called sepsis.

That is why it is important to know how to treat a boil, and when you should see a healthcare provider.


Boils occur when bacteria infect one or more hair follicles and spread into nearby tissues in the skin.

Symptoms of Skin Boils

Boils hurt and itch. A boil is usually diagnosed by its appearance.

A boil is a red, swollen bump surrounded by red, irritated skin. Usually, one or more small whiteheads, called pustules, will form in the center. These are filled with a white or yellow pus-like fluid. Sometimes boils heal without forming a whitehead.

A boil that develops multiple heads is called a carbuncle.

Boils come in all sizes. They may begin pea-sized and can grow to the size of a golf ball. This can happen quickly.

Boils can occur anywhere on the body. They are most common on the face, neck, armpit, buttocks, and thighs.

Your skin may itch before a boil actually appears. Once the boil forms, you may feel fatigued or generally ill. See your healthcare provider if you develop a fever or chills.

Who Is At Risk for Skin Boils?

Boils occur more often in teenagers and young adults. People in communal living situations are also at higher risk. This includes:

  • People living in military barracks
  • People living in homeless shelters
  • People living in other types of close-quarters housing

The spread of the infection in these places can be prevented with antibacterial soaps and good hygiene.

People with certain health conditions are also more likely to get boils. These conditions include:

  • Diabetes, a disease that affects your body's ability to control blood sugar
  • Skin conditions like eczema
  • Poor nutrition
  • Obesity, or having an excessive amount of body fat
  • A weakened immune system, such as in people taking drugs that suppress the immune system

Athletes who play contact sports or share equipment also have an increased risk of spreading the bacteria that cause boils.

It is possible for boils to occur only once. Some people, though, get them repeatedly. 

One study found that up to 10% of people who get a boil will develop another one within a year. Some conditions, like diabetes, make recurrence more likely.


Boils are more common in teenagers, young adults, and people in communal living situations. Some medical conditions may also increase the risk of developing boils.

Treatment For Skin Boils

Treatment for a skin boil depends on the cause. A MRSA infection, for example, will need to be treated by a healthcare provider.

There are some first aid tips you can try at home to make boils more tolerable. These may help them heal on their own.

First, keep the boil clean. Cover it with a clean, dry dressing. Wash your hands after touching the boil or changing the dressing.

Place a warm, moist cloth on the boil. This might help it come to a head, break open, drain, and heal.

Do not pop the boil or try to drain it yourself. It should break and drain naturally.

Never reuse a cloth you used on a boil unless it has been washed in hot water. Do not share items that have been in contact with the boil. Be sure to wash everything that touched the boil in hot water.

When to See a Healthcare Provider

See your healthcare provider if:

  • The boil is on your spine or your face
  • The boil doesn't heal within two weeks
  • You have fever or chills
  • The boil is painful or in an uncomfortable spot
  • The boil develops a red streak

The healthcare provider can drain a larger boil and help with the pain. Antibiotics can be used to reduce the infection. This is not typical, though.


Skin boils are usually caused by bacteria. When the bacteria infect a hair follicle, it forms a red swollen bump. These bumps may develop whiteheads.

Boils occur most often in teenagers and young adults, and in people in communal living situations. People who are obese, have poor nutrition, or have weakened immune systems are also at higher risk.

Boils should be kept clean. Cover them with a warm, damp towel to encourage them to break and drain. Severe boils can be drained by a healthcare provider. Antibiotics may also help.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ibler KS, Kromann CB. Recurrent furunculosis - challenges and management: a review. Clin Cosmet Investig Dermatol. 2014;7:59-64. doi:10.2147/CCID.S35302

  2. Cleveland Clinic. Boils & carbuncles. Reviewed April 15, 2016

  3. Ilyas M, Maganty N, Ginsberg Z, Sharma A. Skin infections due to bacteria in solid organ transplant recipients: a review. Dermatology. 2017;233:358-365. doi:10.1159/000484405

  4. Shallcross LJ, Hayward AC, Johnson AM, Petersen I. Incidence and recurrence of boils and abscesses within the first year: a cohort study in UK primary careBr J Gen Pract. 2015;65(639):e668-e676. doi:10.3399/bjgp15X686929

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.