Joints are the structures that connect two or more bones in your body. They’re found in your feet, ankles, knees, hips, arms, and many other parts of your body.
Joints are surrounded and cushioned by soft tissues. Swelling occurs when fluid accumulates in these tissues. Pain, stiffness, or both may accompany joint swelling. You may also notice that the affected joint appears bigger than normal or irregularly shaped.
Joint swelling can be a symptom of a chronic condition, such as arthritis, or an injury that requires medical attention, such as a dislocation.
One of the most frequent causes of joint swelling is arthritis. Some of the most common types of arthritis include:
Joint swelling can also result from other chronic conditions, illnesses, or acute injuries.
Osteoarthritis is the most common type of arthritis. It’s caused by the natural deterioration of joint cartilage over time.
When the cartilage surrounding your joint wears away, the bones rub up against each other. This can result in joint swelling, pain, and stiffness.
Approximately 1.5 million people in the United States have rheumatoid arthritis (RA), according to the Arthritis Foundation. This inflammatory form of arthritis is also an autoimmune disorder — a type of condition in which your body attacks its own healthy tissues.
If you have RA, your immune system attacks the membranes that line your joints, causing fluid to build up and your joints to swell. It can damage the cartilage, tendons, and ligaments in your joints.
In gout, an increase of uric acid in your blood can result in the deposit of uric acid crystals in your joints, leading to joint swelling and pain. This painful condition can be acute or chronic.
Gout affects about 6 million men and 2 million women in the United States, or about 4 percent of American adults, reports the Arthritis Foundation.
Uric acid is a by-product that your body creates when breaking down certain substances in food. It normally dissolves in your blood and exits your body through urination.
When it isn’t excreted properly, it can build up in your joints, where it forms needle-like crystals. This causes the symptoms of gout, including joint swelling.
Psoriatic arthritis is a type of arthritis that can accompany the skin condition psoriasis.
The Arthritis Foundation estimates that about 30 percent of people with psoriasis have psoriatic arthritis. It’s an autoimmune condition, in which your immune system attacks healthy tissue in your joints and skin. This results in inflammation, causing joint swelling, pain, and stiffness.
Joint swelling can also result from an infection in your joints, caused by bacteria, viruses, or fungi. This type of joint swelling is called septic arthritis. According to the Mayo Clinic, the most common cause of septic arthritis is infection by Staphylococcus aureus bacteria.
Septic arthritis can be chronic or acute. Chronic septic arthritis is rare.
Many other types of arthritis can cause your joints to swell, as can other health conditions. Examples include:
- injuries, such as bone fractures, dislocations, torn ligaments, and torn tendons
- ankylosing spondylitis, a chronic disease that causes joint inflammation
- systemic lupus erythematosus (lupus), an autoimmune disorder that causes inflammation
- hypothyroidism (underactive thyroid)
- sarcoidosis, a disease in which clusters of inflammatory cells collect in your body
- rheumatic fever, an inflammatory disease that results from untreated strep throat or scarlet fever
- tendinitis, inflammation of a tendon
Make an appointment with your doctor if you experience joint swelling that:
- occurred after a serious injury or causes your joint to look disfigured
- has no apparent cause
- is accompanied by severe pain
- is accompanied by a fever
- doesn’t subside or becomes more severe
- interferes with your daily life
When you arrive at your doctor’s office, they’ll likely start by asking you questions about your medical history and symptoms. For example, they may ask:
- when your joint swelling started
- where the swelling has occurred
- how severe the swelling has been
- if anything seems to make the swelling better or worse
- if you have any other symptoms along with joint swelling
Your doctor will also want to examine the affected joints. They may order one or more tests to help determine the cause of the swelling. For example, they may conduct:
- blood tests
- imaging tests, such as X-rays
- joint aspiration, a test in which your doctor will used a needle to draw a small sample of fluid from the affected joint to be analyzed in a laboratory
Your doctor’s recommended treatment plan will depend on the underlying cause of your symptoms.
If your joint swelling occurred following an injury, simple at-home treatments can help relieve your symptoms. Apply ice or a cold pack, wrapped in a cloth, to the affected joint for up to 10 minutes at a time to bring down the swelling.
Apply compression to the joint using an elastic bandage or wrap. Elevate the joint when you’re resting, preferably to a point higher than your heart. Consider taking over-the-counter pain medications to relieve discomfort.
Your doctor may also encourage you to avoid moving or putting weight on the injured joint for a period of time. Ask them how long you should wait before you start using it again.
While it’s important to give your body time to heal, immobilizing the joint for too long can cause your muscle strength and range of motion to deteriorate.
If you’re diagnosed with a chronic condition, such as osteoarthritis or lupus, follow your doctor’s recommended treatment plan. They may recommend medications, physical therapy, or other treatments to help relieve your symptoms and maintain the health of your joint.
Joint swelling is a symptom of many conditions, the most common of which is arthritis. Your joint may also feel painful and stiff or appear larger than usual.
In some cases, the cause of the swelling may be obvious, such as if you recently injured the joint. However, if the cause isn’t apparent, the swelling is severe, or doesn’t subside, set up an appointment with your healthcare provider.
Your healthcare provider can provide you with more information about your specific diagnosis, treatment options, and long-term outlook.