Arthritis in the tendons is called tendinitis or tenosynovitis
When arthritis damages the tendons around your joints rather than the joints themselves, doctors call it tendinitis — inflammation of the tendon tissue. If the sheath that wraps around the tendon becomes inflamed, the condition is called tenosynovitis. Both are common in people with rheumatoid arthritis, and both cause pain, swelling, and stiffness in the hands, wrists, shoulders, knees, and ankles.
The difference matters because it changes how the condition behaves. Tendinitis can develop suddenly or over time. Tenosynovitis tends to be more restrictive because the swollen sheath presses on the tendon itself, sometimes making it hard to move the joint at all. Both can lead to tendon rupture if left untreated — a serious complication where the tendon tears and loses its ability to pull the bone.
Rheumatoid arthritis causes tendinitis and tenosynovitis more often than other types of arthritis because it is a systemic disease that attacks connective tissue throughout the body. Osteoarthritis can cause tendon problems too, but usually as a secondary effect of joint damage rather than as a primary inflammation.
Key Takeaways
- Tendinitis is inflammation of the tendon itself; tenosynovitis is inflammation of the sheath surrounding the tendon.
- Both conditions cause pain, swelling, and reduced movement in the affected joint and are common in people with rheumatoid arthritis.
- Tenosynovitis is often more disabling because the swollen sheath restricts the tendon's movement inside it.
- Untreated tendinitis and tenosynovitis can lead to tendon rupture, which requires surgery to repair.
- Rest, ice, anti-inflammatory medications, and physical therapy are standard first-line treatments for both conditions.
How tendinitis develops in arthritis
In rheumatoid arthritis, the immune system attacks the synovial membrane — the lining that produces fluid to lubricate joints. This same membrane lines the tendons and their sheaths. When inflammation spreads to the tendons, the tissue swells, becomes painful, and loses some of its strength.
The swelling can happen in one tendon or many at once. People with rheumatoid arthritis often develop tendinitis in multiple locations — both wrists, both shoulders, or both ankles — because the disease is symmetrical. The inflammation usually builds slowly over weeks or months, though it can flare suddenly during a disease flare.
Osteoarthritis causes tendon problems differently. As cartilage wears away in a joint, the bones rub together and pull on the tendons that stabilize that joint. The tendon becomes irritated and inflamed as it works harder to compensate for the damaged cartilage. This type of tendinitis is usually localized to one joint.
Tenosynovitis: when the sheath swells
Tenosynovitis is the more restrictive of the two conditions because the tendon sheath is a tight tunnel. When the sheath swells, there is nowhere for the swelling to go — it compresses the tendon inside. This creates a catching or locking sensation, especially in the hands and wrists. Some people describe it as the tendon getting stuck as they try to move.
In the hands, tenosynovitis can make it hard to make a fist or straighten your fingers. In the wrist, it can feel like the joint locks when you try to rotate your hand. The pain is often worse in the morning or after rest, then improves slightly with movement as the fluid warms up and circulates.
Rheumatoid arthritis causes tenosynovitis more often than tendinitis alone because the disease attacks the synovial lining of the sheath directly. If tenosynovitis is not treated, the chronic inflammation can weaken the tendon itself, eventually causing it to rupture without warning — sometimes just from opening a door or lifting a light object.
Symptoms that signal tendon involvement
Tendinitis and tenosynovitis cause pain that is different from typical joint arthritis pain. The pain is often sharp and localized to the tendon itself rather than the joint space. You might feel it along the side of your wrist, the back of your heel, or the front of your shoulder — wherever the tendon runs.
Swelling is visible and often dramatic. The area around the tendon becomes puffy and warm to the touch. In the wrist or hand, the swelling can be so pronounced that your fingers look like sausages. The skin over the swollen area may be red or shiny.
Movement becomes limited and painful. You might not be able to straighten a finger, rotate your wrist, or lift your arm overhead. Some people hear or feel a clicking or popping sensation when they move the affected joint. Morning stiffness is common and can last an hour or more.
When to see a doctor about tendon pain
If you have arthritis and develop sudden sharp pain in a tendon, or if swelling appears around a tendon and does not improve with rest and ice in a few days, contact your rheumatologist or primary care doctor. Tendon problems can worsen quickly, especially in rheumatoid arthritis.
Seek urgent care if you lose the ability to move a joint at all, or if you hear a popping sound followed by sudden loss of strength. This can signal a tendon rupture, which needs imaging and possibly surgery to repair. The sooner a ruptured tendon is treated, the better the outcome.
Your doctor will usually order an ultrasound or MRI to see the tendon and sheath clearly. X-rays do not show soft tissue well, so they are less useful for diagnosing tendinitis or tenosynovitis. Blood tests may be ordered to check inflammation markers if rheumatoid arthritis is suspected.
Treatment options for tendon arthritis
Rest is the first step. If you have tendinitis in your wrist, you may need to wear a splint or brace to keep the joint still while the inflammation settles. Ice applied for 15 to 20 minutes several times a day reduces swelling. Over-the-counter anti-inflammatory medications like ibuprofen or naproxen can help, though people with rheumatoid arthritis usually need stronger medications prescribed by their doctor.
Physical therapy is important once the acute pain subsides. A therapist will teach you gentle stretches and strengthening exercises to restore movement and prevent the tendon from becoming stiff. Therapy also helps you learn how to move in ways that do not re-injure the tendon.
If rest and medication do not work, your doctor may recommend a corticosteroid injection directly into the tendon sheath. This reduces inflammation quickly and can provide relief for weeks or months. For rheumatoid arthritis, controlling the underlying disease with disease-modifying medications often stops tendon problems from developing or worsening.
Preventing tendon problems when you have arthritis
The best prevention is managing your arthritis well. If you have rheumatoid arthritis, taking your disease-modifying medications as prescribed reduces inflammation throughout your body, including in the tendons. People whose rheumatoid arthritis is well-controlled have fewer tendon complications.
Avoid repetitive motions that stress the same tendon over and over. If you type for work and have wrist tendinitis, take frequent breaks and use proper ergonomics. If you have knee tendinitis, avoid activities like running or jumping until the inflammation settles.
Strengthen the muscles around affected joints. Stronger muscles take some of the load off the tendons. Work with a physical therapist to learn exercises that build strength without aggravating the tendon. Stretching before and after activity also helps prevent tendon strain.
Frequently Asked Questions
Can a ruptured tendon heal on its own?
No. A completely ruptured tendon cannot reattach itself. Surgery is needed to sew the tendon back together or to graft a new piece of tendon tissue. The sooner surgery happens after rupture, the better the chance of restoring full function. Partial tears sometimes heal with rest and immobilization, but a complete rupture always requires surgery.
Is tendinitis from arthritis permanent?
Tendinitis can improve or resolve with treatment, especially if caught early. In rheumatoid arthritis, controlling the underlying disease often stops tendon inflammation. However, repeated flares of tendinitis can cause permanent scarring or weakening of the tendon, making it more prone to rupture in the future.
What is the difference between tendinitis and tendonitis?
There is no medical difference — both spellings refer to the same condition. Tendinitis is the more common spelling in modern medical writing, but tendonitis appears in older texts and some medical dictionaries. Your doctor may use either term.
Can I exercise if I have tenosynovitis?
Gentle movement is usually helpful, but high-impact or repetitive exercise can make it worse. Ask your doctor or physical therapist which movements are safe. Typically, you can do gentle range-of-motion exercises, but you should avoid activities that make the pain worse or cause swelling to increase.
Do corticosteroid injections for tendinitis have side effects?
Injections are generally safe when done by a trained doctor, but repeated injections into the same tendon can weaken the tendon tissue over time. Most doctors limit injections to three or fewer per year in the same location. Temporary pain relief, slight bruising, and temporary increase in pain are common short-term effects.