Introduction
The term 'arthritis' simply describes pain or disease that affects the joints – there are over one hundred different types of arthritis which affect people of all ages, although older people and women are generally more affected by the condition.
It is estimated that in Australia 1 in 6 people have some form of arthritis – that's 3.9 million people, with this figure predicted to rise to 5.4 million people by 2030.
Although there are many forms of arthritis, the two most well-known types are osteoarthritis and rheumatoid arthritis.
Causes
The causes of arthritis depend on the type of arthritis…
Osteoarthritis
This is the most common form and is caused by damage to the cartilage in the affected joint either from some form of trauma (i.e. injury) or the slower 'wearing out' of the cartilage over time. Since the role of cartilage is to cushion the ends of bones during movement of the joint, when this is worn down, pain and restricted movement of the joint results. Not only does osteoarthritis affect cartilage, it leads to damage to the bones themselves, connective tissue and the lining of the joint.
Rheumatoid arthritis
On the other hand, rheumatoid arthritis develops when the body's own immune system attacks the 'synovial membrane' – the lining of the joint, which then becomes inflamed.
Metabolic arthritis
Metabolic arthritis refers to arthritis caused by metabolic conditions such as gout.
Reactive arthritis
This is the term used to describe arthritis which is caused by infection. It is more frequently seen in younger patients.
There are a number of known risk factors for arthritis, including…
- Genetic factors - a family history of the condition.
- Age – all types of arthritis (except reactive arthritis) tend to affect older people more than younger people.
- Gender – women are more prone to rheumatoid arthritis than men, although men are more prone to metabolic arthritis (e.g. gout) than women.
- Injury – any injury to a joint will make it more likely that arthritis will affect that joint at some point.
- Body weight – being overweight or obese puts greater strain on the backbone, hips and knees and increases the likelihood of developing arthritis in these joints.
- Issues affecting the immune system and/or the metabolism.
- Repetitive movements of a body joint, for example during sport or in a work environment, can increase the risk of arthritis in that joint.
- Lack of physical activity – people who have a largely sedentary lifestyle are at greater risk of developing arthritis.
- Smoking.
Symptoms
The main symptoms of arthritis are pain affecting a joint, swelling of a joint, and in some cases a decrease in the range of motion of the joint and / or stiffness in the joint.
In some cases, the arthritis causes visible changes in the joint itself (for example the finger joints), but in most cases there is no visible change. Arthritis can vary in its severity and this severity can change over time, with symptoms flaring up and then decreasing. For some people the pain becomes chronic and severely limits daily movement such as walking or climbing stairs.
In some cases, other symptoms develop, for example, feeling tired or ill and in some cases, (otherwise unexplained) loss of weight.
Tests / Diagnosis
The first step is to visit a doctor, where your symptoms will be reviewed and the doctor will conduct a physical examination. Blood tests may be required to detect inflammation and other indicators of the presence of arthritis and a sample may be taken of synovial fluid – the fluid that surrounds the joint. Imaging of the joint via x-ray, CT scan of ultrasound may be needed to detect cartilage loss or any change in the spacing between the bones.
As diagnosis is not always straightforward, you may be referred to an orthopaedic specialist or rheumatologist.