Arthritis is a joint disorder characterized by inflammation that is frequently accompanied by pain. More than 100 types of arthritis exist, but the most commonly diagnosed types are osteoarthritis and rheumatoid arthritis. Joint pain accompanies both. The chief causes of arthritis pain include inflammation, joint tissue damage, muscle strain, fatigue, and depression or stress.

Inflammation

Arthritis causes inflammation of both the synovial membrane tissue that lines the joints, and the tendons and ligaments connected to the affected joints. Stiffness, as well as mild to severe pain, result from this inflammation, limiting the affected person's mobility.

Joint Tissue Damage

Damage to joint tissues also cause arthritic pain. Damage may be caused by trauma, pressure, stress or degeneration from aging.

Muscle Strain

Muscle strain near an arthritic joint increases the level of related arthritic pain. Strains also temporarily decrease mobility and add to stiffness, creating a cycle that leads to continued increase in pain.

Fatigue

Fatigue not only increases the perception of pain, but decreases your ability to tolerate pain. Addressing fatigue will likely reduce associated arthritic pain.

Depression or Stress

Emotional factors such as depression and stress are believed to worsen arthritic pain. Depression typically sets in if patients have to limit enjoyable activities due to mobility issues. This can begin a cycle of pain, limitations, depression and stress that decreases the ability to manage arthritic pain.

Source:

MedicineNet.com: Symptoms of Arthritis

Arthritis Foundation: Causes of Pain

Federal Citizen Information Center: Questions and Answers About Arthritis Pain