How can you know if you have arthritis or just swollen tendons?

Tendon sheath inflammation is typically the result of injury to the tendon or surrounding muscle or bone.
Symptoms include joint stiffness, swelling, and skin redness over affected area.
Some people may develop a fever. This indicates the presence of an infection and requires immediate medical attention.
A tendon is a type of fibrous tissue that connects your muscles to your bones. These tissues help control actions such as running, jumping, grasping, and lifting. Without tendons, you wouldn’t be able to control the movement of your body.

A protective sheath known as the synovium covers tendons. This sheath produces synovial fluid, which keeps the tendon lubricated. Injury to the tendon may result in the malfunction of the sheath. If this occurs, the sheath may fail to make synovial fluid or it may not make enough fluid. This can cause inflammation or swelling of the sheath. This condition is known as tendon sheath inflammation. It’s also sometimes called tenosynovitis.

Tendon sheath inflammation is typically the result of injury to the tendon or surrounding muscle or bone. It’s not limited to athletes and appears in patients who perform a variety of repetitive-motion activities, such as assembly-line work, weeding, and typing. People working in certain jobs appear to have greater risk of it than others, including:

office workers
It’s most common in the tendons of the wrist, hands, and feet. Injury can result from:

repetitive-stress activities
prolonged physical activities, such as running
standing in the same position for long periods of time
sudden sprains and strains
Tendon sheath inflammation can also be due to underlying health conditions. Examples of conditions that can result in this condition include:

rheumatoid arthritis
reactive arthritis, such as Reiter’s syndrome
The cause of the disease can’t be determined in some patients. In rare cases, tendon sheath inflammation is due to an infection that resulted from a cut or puncture to the tendon.