Swelling in a single finger usually results from an injury or minor infection. It may also be a sign of arthritis, gout, or a benign growth.

Swelling in one finger is usually not a cause for concern. However, accompanying symptoms may indicate an underlying issue. Treatment depends on the cause, though applying ice can help soothe any pain and inflammation in many cases.

This article discusses the possible causes of one swollen finger. It also looks at treatment options and when to contact a doctor.

A person who may have one swollen finger is explaining the pain to a healthcare professional.Share on Pinterest
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Breaking, dislocating, or spraining a finger can result in swelling.

If a person has sprained their finger, pain and stiffness alongside the swelling can occur.

If a person has dislocated their finger, the finger may appear crooked. A dislocated finger may cause:

  • pain
  • swelling
  • numbness
  • difficulty moving the finger
  • bruising and skin discoloration

It can be difficult for a person to know whether the finger has a sprain or is dislocated. A person should visit a medical professional as soon as possible if they notice the following symptoms:

  • the finger points at an odd angle
  • the finger appears blue
  • the finger is numb
  • there is a cut and the bone is visible
  • there is a cut and bone pokes out of the finger
  • it is impossible or very difficult to move or bend the finger

Treatment

If a finger appears broken or dislocated, a person needs to get medical attention as soon as possible.

People should not try to move a dislocated finger back into the joint themselves. It can cause further damage. A healthcare professional can put the bone back in the joint and fit a splint or cast to keep it in position.

For complicated breaks, surgery may be the best option. A surgeon may insert small pins, screws, or rods into the finger to hold the fractured bones together while they heal.

For a mild sprain, rest, ice, compression, and elevation (RICE) techniques can help reduce swelling and inflammation.

A person may also strap the finger to the one next to it to prevent bending and further injury. If the finger has swollen a lot, wait until the swelling subsides before taping it.

Mallet finger, also known as baseball finger, describes an injury to the tendon at the end of the finger.

This tendon usually helps the finger straighten. An injury to the top of the finger can cause the tendon to rupture, resulting in swelling, pain, and bruising.

A doctor can order X-rays to check the damage to the finger and use a splint to straighten the finger until it heals.

Many infections can cause the finger to become swollen, painful, and hot.

An infection near the nail bed can cause swelling and tenderness. This is called paronychia.

The following may cause paronychia:

If a person gets a superficial cut on the finger, washing it with soap and water as soon as possible can prevent infection.

Insect bites or stings directly to the finger can cause swelling, pain, and inflammation around the site. Occasionally, stings or bites can develop into an infection if bacteria enter.

Symptoms include:

  • tenderness
  • heat
  • discharge or pus from the bite

Erythema also occurs around the site of infection. On lighter skin, this appears as red. On darker skin, the surrounding area may look purple or burgundy.

Treatment

Bacterial infections typically require antibiotics.

A healthcare professional may also need to drain pus from the infected area with a small incision. Soaking the affected finger in warm, salted water may also help, as well as taking pain relievers, such as ibuprofen and acetaminophen.

It is best to get medical attention if swelling and erythema develop quickly after an insect bite or sting. These symptoms can be a sign of an allergy rather than an infection.

According to the Centers for Disease Control and Prevention (CDC), an average of 72 people in the United States died because of allergic reactions to insect stings from 2011–2021.

There are a few benign, or noncancerous, hand tumors that can appear in the hands and fingers, causing swelling.

These include:

Enchondroma

This is a bone tumor that begins in the cartilage. It typically affects the long, small bones of the hands and feet.

Enchondroma is most common in people of middle age, though it can occur at any age.

Symptoms include:

  • hand pain if the tumor is large
  • finger enlargement
  • slow bone growth

Ganglion cyst

This is a fluid-filled cyst that forms next to a joint or tendon. Although ganglion cysts typically appear on the back of the wrist, they can also develop at the base of the finger.

They can change in size. Although harmless, they can cause pain or a dull ache.

If the cyst ruptures, the area may become swollen and sore.

Epidermal inclusion cyst

Epidermal inclusion cysts are fibrous cysts formed from keratin and dead skin cells. They present as flesh-colored, firm nodules.

They can occur anywhere on the body, including the fingers.

Giant cell tumor

This is a solid mass that typically forms next to a tendon.

According to a 2019 research article, giant cell tumors in the hand are rare, making up only 2% of all hand tumors.

A giant cell tumor can resemble an enchondroma. Doctors sometimes find it challenging to make a correct diagnosis.

The 2019 article notes that giant cell tumors on the hand grow quickly and have a high recurrence rate.

These tumors do not always cause swelling and inflammation, but they can cause localized pain and limited movement.

Treatment

Treatment depends on the type of growth.

Enchondromas may require surgery or bone grafting. If there is no sign of growth or weakening of the bone, a healthcare professional may recommend watchful waiting.

Ganglion cysts do not typically require treatment. However, if it is large or causing discomfort, a healthcare professional may drain the cyst or surgically remove it.

Epidermal inclusion cysts and giant cell tumors require surgical intervention.

If a person notices a growth appearing, they should see a medical professional to get a correct diagnosis.

Gout is a common type of inflammatory arthritis that can cause pain and swelling in one joint at a time.

People with gout have high uric acid levels, causing crystals to build up in the body’s joints and tissues.

Symptoms include:

  • intense pain
  • swelling
  • heat
  • erythema

Treatment

A person can treat gout with medication, such as:

A person can also change their diet and lifestyle to treat gout and flare-ups, such as eating a balanced diet and getting plenty of physical activity.

Rheumatoid arthritis (RA) is an immune system disorder that attacks the joints, causing inflammation, swelling, and pain. It typically affects the hands, wrists, and feet.

Stiffness, tenderness, pain, or swelling in one or two fingers, often around the middle and the base of the fingers, can be early symptoms of RA.

Inflammation from RA can also cause an increase in joint fluid, making swelling worse.

Treatment

There is no cure for RA, but treatment can help reduce symptoms and prevent flare-ups.

Medication may include:

  • disease-modifying antirheumatic drugs (DMARDs)
  • biological response modifiers, also called immunomodulators
  • self-management strategies to help reduce pain and increase mobility

Septic arthritis is an infection in the fluid and tissues around the joint that causes arthritis-like symptoms. It can occur due to injury, surgery, or bacteria traveling from another area of infection to the joints, such as a finger.

As well as joint pain and swelling, symptoms may include:

  • fever
  • reddening or purpling around the joint
  • warmth

Without treatment, septic arthritis can result in permanent joint damage, so it is essential to get a diagnosis as soon as possible.

Treatment

A person’s age and general health may affect the treatment for septic arthritis. The severity of the infection may also affect treatment options.

Treatment usually includes a combination of:

  • antibiotics
  • draining pus from the joint
  • medication to relieve pain and fever
  • a splint on the affected joint

Other very rare causes of a single swollen finger include:

  • Osteoarticular tuberculosis (TB): According to a 2015 article, osteoarticular TB represents 5% of all cases of TB. A swollen finger is a rare symptom of TB.
  • Reflex sympathetic dystrophy (RSD): RSD is a rare nervous system disorder that can cause swelling and burning pain in one joint, often in the finger.
  • Sarcoidosis: An inflammatory condition, sarcoidosis can cause a swollen finger.
  • Malignant tumors: Malignant, or cancerous, tumors in the hands and wrists can also cause swelling in the finger.

A person can treat some causes of a swollen finger at home.

However, people should seek medical advice as soon as possible if they suspect a broken or dislocated finger, or if there is any sign of infection.

Here are some frequently asked questions about swelling in one finger.

How do I know if my finger pain is serious?

There are a variety of reasons that may contribute to finger pain, some of which are serious and need medical attention.

Seek medical care if any of the following occur:

  • considerable pain
  • significant swelling
  • finger appears blue
  • finger is numb
  • there is visible bone

How long should a swollen finger last?

The duration of swelling depends on the cause. If a person suspects a broken finger or if there is a sign of infection due to worsening or lasting swelling, they need to seek medical advice.

Why is one finger swollen with no injury?

One finger swollen by itself with no injury may result from an infection, growth, or an underlying condition, such as arthritis.

Many causes and health conditions can cause a single finger to swell, but most are not serious.

RICE techniques can help treat a swollen finger at home, though it may be necessary to visit a healthcare professional for further tests and treatment.

There may be a more serious underlying cause for a swollen finger. Some people may require further medical treatment.