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Swollen Thumb: Causes & Treatments

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A swollen thumb may be painful and affect your day-to-day activities. Causes for a swollen thumb can arise from a bacterial infection within the nail, trauma from a injury that is affecting the thumb bones, or inflammation of the thumb joints. A sprained thumb and arthritis are the most common culprits for a swollen thumb. Read below for more information on causes and treatment options.

8 most common causes

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Common swollen thumb symptoms explained

Swelling of the thumb can be debilitating, since the thumb is so important for daily activities such as writing and manipulating objects. Unfortunately, the swollen thumb is often painful and stiff, and strength may be decreased. Swelling may occur due to conditions involving the skin, ligaments, bones, or joints between bones in the thumb. Many causes of thumb swelling can be expected to resolve with appropriate treatment.

Common accompanying symptoms of a swollen thumb

Symptoms that can be associated with a swollen thumb include [1,2]:

  • Pain
  • Redness
  • Drainage of pus
  • Small blisters
  • Stiffness or weakness of the thumb
  • Swelling of a thumb joint or at the tip of the thumb

What causes thumb pain and swelling?

Infectious causes

A swollen thumb may occur due to an infection like the following.

  • Bacterial infection: The skin surrounding the thumbnail can develop a bacterial infection, causing pain, redness, and swelling. Thumb swelling can also be caused by a bacterial infection of the pad of the thumb; if untreated, this infection can progress to underlying structures such as the bone. Thumb joints can also be infected by bacteria.
  • Viral infection: The thumb can be infected by herpes virus via thumb sucking or nail biting when the mouth has active herpes lesions (cold sores). The infected thumb will be swollen, extremely painful, and small blisters will be present.

Injury-related causes

Any type of injury to the structures of the thumb, including bone and ligaments, can potentially cause swelling.

  • Ligament sprain: A major ligament of the thumb can be injured when the thumb is forcefully pulled away from the rest of the hand, such as when you are trying to catch yourself during a fall. The thumb will be tender, bruised, and swollen.
  • Bone fracture: One of the thumb bones can be broken during a fall or through trauma from an athletic event.
  • Bone dislocation: The bone at the base of the thumb can be knocked out of its normal position relative to the adjacent bone of the hand, leading to swelling, pain, and an abnormal angle of the thumb.

Chronic joint disorders

Chronic disorders of the joints can manifest in the thumb leading to swelling.

  • Arthritis: Multiple types of arthritis can cause swelling of the thumb joints, resulting in swelling, pain, and stiffness.
  • Gout: An acute attack of gout can cause swelling and severe pain. If gout is poorly controlled over a long period of time, it can also cause hard swelling of a joint, which can enlarge and interfere with movement of the thumb.

Tumors

Tumors in the area of the hand or thumb can result in swelling.

  • Bone tumor: Very rarely, a swelling of the thumb could be a benign or cancerous tumor of the bone. In this case swelling develops gradually, along with pain and decreased ability to move the thumb.
  • Metastasis: Also rarely, a swelling of the thumb may be a metastasis of cancer from another site in the body. Lung cancer is the most typical primary cancer.

This list does not constitute medical advice and may not accurately represent what you have.

How to relieve a swollen thumb

When a swollen thumb is an emergency

Seek emergency swollen thumb treatment if:

  • You have severe swelling, pain, or numbness after an injury, and/or the thumb appears to be at an abnormal angle: Quick treatment will help prevent long-term complications
  • You have rapidly progressing swelling and pain of a thumb joint: It is especially important to get immediate treatment if you also have a fever or other signs of systemic illness.

When to see a doctor for a swollen thumb

In some cases, even though emergency care isn't necessary, you may need medical evaluation and treatment. Make an appointment with your medical provider if:

  • You have decreased ability to carry out daily activities: Due to stiffness, weakness, or pain of the thumb
  • You have thumb swelling that is worsening or staying the same over time
  • You have another condition: You have previously been diagnosed with arthritis, gout, or cancer and have new thumb swelling.
  • You have drainage from the thumb

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Medical treatments for a swollen thumb

Your medical provider may prescribe one or more of the following treatments, depending on the cause of the swollen thumb symptoms:

  • Antibiotics and drainage: For a bacterial infection
  • Antiviral medication: For a viral infection
  • Treatment for an underlying medical condition: Such as arthritis or gout
  • A splint: To ensure normal healing after an injury
  • Referral for surgical management
  • Steroid injection for arthritis

At-home treatments for a swollen thumb

Some home treatments may help with swollen thumb symptoms, such as the following.

  • Ice: Applying an ice pack for up to 15 minutes a few times a day can help ease pain and swelling due to arthritis or an injury.
  • Avoid certain food and drinks: Avoiding shellfish, red meat, and alcohol can help prevent attacks of gout.
  • Use pain relievers: Ibuprofen (Advil, Motrin) or other NSAIDs can help with swelling and pain due to arthritis or an injury.
  • Soaking: Soaking the thumb in warm water can help with pain, swelling, and stiffness.

Thumb arthritis

Arthritis of the thumb is common with aging and occurs when cartilage wears away from the ends of bones that form the thumb joint. This can cause severe pain, swelling and decreased strength and range of motion, making it difficult to do simple tasks, such as turning doorknobs and opening jars.

You should visit your primary care physician to confirm the diagnosis and discuss treatment options for managing symptoms.

Sprained thumb

Ligaments are strong bands of tissue that hold together bones at joints. The thumb has several ligaments that support it, and these ligaments may get sprained if a person breaks a fall with their thumb. When ligaments become sprained, they do not necessarily tear. Low-grade (or mild) sprains happen when microscopic tears appear in the ligament, causing pain. A sprained thumb may limit a person's ability to grasp items. Other symptoms can involve bruising, tenderness, and swelling.

You should visit your primary care physician for an X-Ray. Although often a sprained thumb may be ignored with the hope that it will heal itself, if a ligament injury is not diagnosed and treated correctly, chronic instability may result.

Rheumatoid arthritis

Rheumatoid arthritis is a chronic inflammatory disorder that affects the lining of the joints, causing them to become thickened and painful. It can also affect other parts of the body such as the heart, lungs, eyes, and circulatory system.

Rheumatoid arthritis is an autoimmune disease, which means the body's immune system turns against itself for unknown reasons.

Most at risk are women from ages 30-60. Other risk factors are family history, smoking, and obesity.

Early symptom include warm, swollen, stiff, painful joints, especially the fingers and toes; fatigue; and fever. Usually, the same joints on both sides of the body are affected.

If untreated, irreversible joint damage and deformity can occur, with other complications. Early diagnosis can allow preventive treatment to begin as soon as possible.

Diagnosis is made through physical examination; blood tests; and x-ray, CT scan, or MRI.

There is no cure for rheumatoid arthritis, but the disease can be managed to improve quality of life. Treatment includes nonsteroidal anti-inflammatory drugs; steroids; anti-rheumatic drugs; physical therapy; and sometimes surgery to repair the joints.

Psoriatic arthritis

Psoriatic arthritis is a complication of psoriasis, which causes the skin to become thickened, red, and scaly. Arthritis may appear before or after the psoriasis appears.

Both conditions are autoimmune diseases, where the body attacks itself, and are thought to be caused by genetic and environmental factors.

Most susceptible are people from 30 to 50 years of age with a family history of the disease and who already have psoriasis.

Symptoms include the joints on one or both sides of the body becoming painful, swollen, and hot; swelling and deformity of the fingers and toes; pitted, flaking fingernails; foot pain in the heels and soles; and joint pain in the low back pain.

It is important to seek treatment, as psoriatic arthritis can permanently damage the joints, eyes, and heart.

Diagnosis is made through physical examination, x-rays, and MRI. Blood tests and joint fluid tests can confirm psoriatic arthritis.

Treatment includes over-the-counter, nonsteroidal anti-inflammatory drugs; anti-rheumatic medication; immunosuppressants; and steroid injections for the joints. Surgery to replace damaged joints may also be tried.

Non-serious finger injury

Finger injuries are very common & rarely need medical treatment.

You can treat this at home with ice and rest. An X-ray would be necessary to rule out a fracture if you had swelling and difficulty moving the finger.

Rarity: Common

Top Symptoms: recent finger injury, finger pain from an injury, swollen finger, severe finger pain

Symptoms that always occur with non-serious finger injury: recent finger injury

Symptoms that never occur with non-serious finger injury: bent or crooked finger

Urgency: Self-treatment

Jammed thumb

Jammed thumbs are common in sports but may occur during daily activity.

You should visit a physician or urgent care center in the next day. Generally, surgery is not required and splinting is sufficient.

Rarity: Uncommon

Top Symptoms: thumb injury, thumb pain from an injury, swollen thumb, finger bruise

Symptoms that always occur with jammed thumb: thumb injury, thumb pain from an injury

Urgency: Primary care doctor

Dupuytren disease

Dupuytren disease, also known as Dupuytren's contracture, is a condition that causes tissue under the skin of the palm to thicken. This thickening can occur slowly over many years. Its cause is not known, but it is more common in men and people over the age of 40. Symptoms include hard bumps or bands of tissue under the skin, finger stiffness, and trouble fully straightening the fingers.

You should consider visiting a medical professional to discuss your symptoms. Dupuytren disease can be evaluated with a review of your symptoms and a physical exam. Once diagnosed, symptoms of mild cases can be relieved with hand exercises, warm baths, and stretching. More severe cases can be treated with steroid injections, surgery, radiation therapy, or a needling procedure.

Rarity: Uncommon

Top Symptoms: finger joint stiffness, hand bump, thickened skin on the finger, swollen hands, hand injury

Urgency: Primary care doctor

Swollen thumb quiz

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Cellulitis

Cellulitis is a bacterial infection of the deep layers of the skin. It can appear anywhere on the body but is most common on the feet, lower legs, and face.

The condition can develop if Staphylococcus bacteria enter broken skin through a cut, scrape, or existing skin infection such as impetigo or eczema.

Most susceptible are those with a weakened immune system, as from corticosteroids or chemotherapy, or with impaired circulation from diabetes or any vascular disease.

Symptoms arise somewhat gradually and include sore, reddened skin.

If not treated, the infection can become severe, form pus, and destroy the tissue around it. In rare cases, the infection can cause blood poisoning or meningitis.

Symptoms of severe pain, fever, cold sweats, and fast heartbeat should be seen immediately by a medical provider.

Diagnosis is made through physical examination.

Treatment consists of antibiotics, keeping the wound clean, and sometimes surgery to remove any dead tissue. Cellulitis often recurs, so it is important to treat any underlying conditions and improve the immune system with rest and good nutrition.

Rarity: Uncommon

Top Symptoms: fever, chills, facial redness, swollen face, face pain

Symptoms that always occur with cellulitis: facial redness, area of skin redness

Urgency: Primary care doctor

FAQs about swollen thumb

Can a swollen thumb be due to an infection?

Yes, the thumb may swell due to an infection. A bacterial infection of the skin around the thumbnail or the pad of the thumb can cause swelling,redness, and pain. The thumb joints can also be infected by bacteria, especially if there was a preceding injury that broke the skin. In addition, the thumb can be infected by herpes virus after exposure to cold sores in the mouth.

Why does gout cause a swollen thumb?

Attacks of gout occur periodically due to high levels of uric acid. Crystallization of this substance within a joint, such as a thumb joint, causes inflammation that then leads to swelling and severe pain. If you have gout over a long period of time and it is not well controlled with medications, crystals can bind with other substances to create a large, hard nodule within the joint.

What kinds of injuries cause a swollen thumb?

Any type of injury to the structures that make up the thumb will likely lead to swelling. One common injury is a sprain of the ulnar collateral ligament, which stabilizes the joint at the base of the thumb. A thumb bone can be fractured, or the bone at the base of the thumb can be dislocated.

Will I need surgery to fix a swollen thumb?

In some cases, surgery is necessary to address the cause of a swollen thumb. Serious injuries may require surgical management, such as if the major ligament of the thumb is completely torn. Surgery may also be indicated for severe arthritis that is uncontrolled by other treatments. In the rare case that swelling of the thumb is caused by a tumor, surgical removal will likely be required.

Why is my thumb swollen and stiff?

When stiffness is present in addition to swelling, arthritis is the most likely cause. Arthritis of the thumb is most commonly due to osteoarthritis, which tends to occur with aging. However, thumb arthritis can also occur as part of rheumatoid or psoriatic arthritis. Any type of thumb arthritis will involve pain, stiffness, and swelling, resulting in difficulty using the thumb for daily activities such as gripping objects.

Questions your doctor may ask about swollen thumb

  • Have you ever been diagnosed with diabetes?
  • Have you ever been diagnosed with cancer?
  • Do you have these contractures that limit the movement of your fingers? (See picture)
  • Do any of your body parts (e.g., toes, hands, ears) feel cold?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.

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Dr. Rothschild has been a faculty member at Brigham and Women’s Hospital where he is an Associate Professor of Medicine at Harvard Medical School. He currently practices as a hospitalist at Newton Wellesley Hospital. In 1978, Dr. Rothschild received his MD at the Medical College of Wisconsin and trained in internal medicine followed by a fellowship in critical care medicine. He also received an MP...
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