The term arthralgia literally means joint pain. It is a combination of two Greek words – Arthro – joint and algos – pain.

There are several reasons why joints can be painful. It could be due to:-

• injury
• infection
• immune disorders
• allergic reactions
• degenerative diseases

However, according to the Medical Subject Headings created by the United States National Library of Medicine, the term “arthralgia” should not be generalized to all conditions and should be reserved for the cases where there are no inflammatory pathologies affecting the joints. Where there is presence of inflammation, the condition should be termed arthritis.

Types and pathologies of arthralgia

Despite the convention Inflammatory arthralgia is commonly used to describe inflammatory joint pain. Many of these individuals may be actually suffering from osteoarthritis.

Osteoarthritis is a degenerative joint disease that is the commonest form of arthritis. In this condition there is loss of the cushion like cartilage that is placed between the ends of the bones at the joints to allow for smooth and painful movements.

Prevalence of osteoarthritis rises with age. With continued use the cartilage may be irritated and this may lead to pain and swelling. With progressive loss of the cartilage the ends of the bones undergo friction leading to loss of joint mobility as well.

Pain from osteoarthritis is worse after activity and at the end of the day. There is presence of stiffness in the morning or after inactivity that lasts for a few minutes.

Those with inflammatory arthralgia have a typically different presentation. The stiffness in these cases tends to last more than an hour.

Unlike osteoarthritis that affects joints on one side of the body and usually affected major weight bearing joints like the knees, hips, ankles etc., inflammatory arthralgias affect smaller joints of the hands and feet more commonly and joints on both sides of the body usually are involved.

The redness, swelling and warmth near the joint is seen more prominently with osteoarthritis than inflammatory arthralgias.

Autoimmune conditions that are responsible for inflammatory arthralgias include rheumatoid arthritis, scleroderma, systemic lupus erythematosus, Sjögren’s disease and mixed connective tissue disease.

In these conditions the body’s immune system perceives the joint and its proteins as foreign and attacks them causing severe joint damage. These are progressive conditions that eventually lead to tissue damage and fibrous scarring over the joints and severe loss of mobility.