What is Arthritis? What Causes Arthritis
The word arthritis comes from the Greek arthron meaning "joint" and the Latin itis meaning "inflammation". The plural of arthritis is arthritides. Arthritis affects the musculoskeletal system, specifically the joints. It is the main cause of disability among people over fifty-five years of age in industrialized countries.
Arthritis is not a single disease - it is a term that covers over 100 medical conditions. Osteoarthritis (OA) is the most common form of arthritis and generally affects elderly patients. Some forms of arthritis can affect people at a very early age.
What causes arthritis?
In order to better understand what is going on when a person suffers from some form of arthritis, let us look at how a joint works.
Basically, a joint is where one bone moves on another bone. Ligaments hold the two bones together. The ligaments are like elastic bands, while they keep the bones in place your muscles relax or contract to make the joint move.
Cartilage covers the bone surface to stop the two bones from rubbing directly against each other. The covering of cartilage allows the joint to work smoothly and painlessly.
A capsule surrounds the joint. The space within the joint - the joint cavity - has synovial fluid. Synovial fluid nourishes the joint and the cartilage. The synovial fluid is produced by the synovium (synovial membrane) which lines the joint cavity.
If you have arthritis something goes wrong with the joint(s). What goes wrong depends on what type of arthritis you have. It could be that the cartilage is wearing away, a lack of fluid, autoimmunity (your body attacking itself), infection, or a combination of many factors.
Types of arthritis
There are over 100 types of arthritis. Here is a description of some common ones, together with the causes: • Osteoarthritis - cartilage loses its elasticity. If the cartilage is stiff it becomes damaged more easily. The cartilage, which acts as a shock absorber, will gradually wear away in some areas. As the cartilage becomes damaged tendons and ligaments become stretched, causing pain. Eventually the bones may rub against each other causing very severe pain. • Rheumatoid arthritis - this is an inflammatory form of arthritis. The synovial membrane (synovium) is attacked, resulting in swelling and pain. If left untreated the arthritis can lead to deformity. Rheumatoid arthritis is significantly more common in women than men and generally strikes when the patient is aged between 40 and 60. However, children and much older people may also be affected. • Infectious arthritis (septic arthritic) - an infection in the synovial fluid and tissues of a joint. It is usually caused by bacteria, but could also be caused by fungi or viruses. Bacteria, fungi or viruses may spread through the bloodstream from infected tissue nearby, and infect a joint. Most susceptible people are those who already have some form of arthritis and develop an infection that travels in the bloodstream. • Juvenile rheumatoid arthritis (JRA) - means arthritis that affects a person aged 16 or less. JRA can be various forms of arthritis; it basically means that a child has it. There are three main types: 1. Pauciarticular JRA, the most common and mildest. The child experiences pain in up to 4 joints. 2. Polyarticular JRA affects more joints and is more severe. As time goes by it tends to get worse. 3. Systemic JRA is the least common. Pain is experienced in many joints. It can spread to organs. This can be the most serious JRA.
What are the signs and symptoms of arthritis?
The symptoms of arthritis depend on the type of arthritis, for example: • Osteoarthritis - The symptoms develop slowly and get worse as time goes by. There is pain in a joint, either during or after use, or after a period of inactivity. There will be tenderness when pressure is applied to the joint. The joint will be stiff, especially first thing in the morning....
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