The two most common occurrences of this disorder are in the form of 'housemaid's knee' and bursitis of the shoulder. The pain arises due to inflammation of the bursae, which are specially lined, closed sacs designed to lubricate the areas where muscles rub against joints.

In the case of housemaid's knee it is the prolonged kneeling, which creates pressure on the bursae and results in inflammation.

Where the shoulder is involved, it is the inflammation of the tunnel through which the tendons pass, which causes the problem. This is why, only when the arm is in certain positions, pain is experienced because the bursae are only compressed in the tunnel at certain stages of movement.

This is the form of arthritis in which extremely painful inflammatory attacks can occur as a result of the participation of uric acid crystals from the blood. It usually affects the wrists, knees or feet, being most common probably in the joints of the big toe. In contrast to rheumatoid arthritis, gout is more commonly found in men than in women. When it does occur in women it is usually in the post-menopausal phase of life.

Traditionally the cause of gout has been linked to high living. This may well be true since the consumption of large rich meals accompanied by plenty of alcohol would stimulate production of uric acid and concurrently inhibit its disposal by the kidney. However, many gout sufferers lead a very moderate lifestyle and suffer the disorder due to some defect in their system, which allows the build-up of the uric acid in the bloodstream to reach a level at which its solubility is exceeded and it therefore crystallizes out. The pain is caused by the physical presence of the acid crystals in the joint lining.

These terms refer to painful conditions that are technically not arthritis and are used to describe non-specific back or neck pains. In the case of lumbago it is the lower back, which is involved. The conditions can occur in anyone and are sometimes related to heavy lifting, back posture, sleeping with a pillow at a wrong height and so on. The individuals who have these syndromes experience stiffness, pain around the joints, easy fatigability and sleep disturbances. The cause is not known but is probably associated with some degeneration of spinal cartilage.

An unfortunate side effect of the condition is that there is no physical manifestation of the problem and the idea that someone is merely shrinking duties by claiming to have back troubles can be psychologically upsetting to the genuine sufferer.

This is a relatively rare condition of older people, usually not occurring before the age of 50. There is stiffness in the muscles of the hips, thighs, shoulders and neck as well as pain particularly in the morning, making movement difficult.

Although the cause is unknown, it is often associated with rheumatoid arthritis, systemic lupus erythematosus (SLE), temporal arthritis and cancer.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease in which the immune system attacks itself, killing healthy cells and tissue, rather than doing its job to protect the body from disease and infection. SLE can inflame and damage a person's joints, skin, kidneys, lungs, blood vessels, heart, and brain.

Causing inflammation and weakness in the muscles, this disease can affect the whole body and cause disability.

This is a form of the disease in which two separate conditions exist simultaneously. The psoriasis is a skin condition in which patches of red, flaky skin appear, most frequently in areas such as the scalp, elbow and knees.

It often coincides with rheumatoid arthritis and opinions differ as to whether the two conditions are actually associated or merely coincidental. There is evidence to suggest that the condition may involve a hereditary factor as well.