Rheumatoid arthritis (RA) and Osteoarthritis (OA)

“Until I was diagnosed, I thought that ‘arthritis’ was just something that old people get.”  

Until you or someone close to you is diagnosed with rheumatoid arthritis (RA), unfortunately, this is most people’s perception of the disease. This is, at least in part, because many people, including some healthcare professionals, still refer to ‘osteoarthritis’ as ‘arthritis’. So what’s the difference? 

Osteoarthritis is by far the most common type of arthritis. There are over 200 forms of arthritis, and the word arthritis simply means ‘inflammation of the joint’. The reasons for that inflammation, however, varies between the different forms. In the case of osteoarthritis, the cause is ‘wear and tear’ of the joints, making the condition more common among the older population, though it is possible to get it earlier in life, especially in a previously damaged joint. RA is an auto-immune condition, meaning that the immune system, normally there to protect us, is attacking healthy tissue, in this case, the lining of the joints. It can occur at any age, though the typical age of onset is around 40-60, and the exact causes of this immune response are unknown, though we do know that genetics and environmental factors play a part.  

One third of people over the age of 45 in the UK have sought treatment for osteoarthritis, whereas RA affects a much smaller number, at around 1% of the UK population.  

Rheumatoid arthritis is a ‘systemic’ condition, meaning that it has an effect on the body as a whole, whereas osteoarthritis tends only to affect individual joints. Both can cause symptoms such as pain and stiffness in the joints, but rheumatoid arthritis can also cause systemic symptoms, such as flu-like symptoms and fatigue. The stiffness that occurs in the joints also differs between conditions. In osteoarthritis, this symptom often occurs towards the end of the day, after using the affected joint, whereas in RA the stiffness is worse after periods of inactivity, especially in the morning, when it can be severe and last for more than thirty minutes.  

There are also differences between the joints affected by these two conditions. Rheumatoid arthritis tends to affect joints symmetrically, most commonly the small joints of the hands and feet. Multiple joints may be affected, sometimes simultaneously, whereas OA will be isolated to individual joints. Osteoarthritis can affect the lower parts of the spine, and the finger joints closest to the nailbeds, both of which are areas of the body rarely affected in RA. RA can affect different joints at different times, whereas osteoarthritis doesn’t come and go, although pain and stiffness can come and go. 

With all these differences in cause, progression, symptoms and location in the body, it is understandable that these conditions are also treated very differently. RA tends to be treated in secondary care, whereas osteoarthritis is normally managed by the GP. While both conditions can benefit from symptom relief, using painkillers and anti-inflammatories and non-medicinal relief, such as hot or cold packs applied to painful joints. Drugs known as disease-modifying anti-rheumatic drugs (DMARDs) are used to try to stop RA worsening, by dampening down the over-active immune system.  

Let’s face it. There is no ‘good’ form of arthritis to get, but it can be frustrating telling people about your diagnosis and having it so commonly mistaken for a more common and often less severe condition, but knowing some of the basic differences yourself can help you to explain RA to friends, family and colleagues.