It’s easy to dismiss knee pain. Perhaps you overdid it at last weekend’s Parkrun. Maybe you’ve been struggling with joint issues for a while and have simply put them down to getting older.
But what if there’s no clear reason for the pain you’re experiencing? That’s to say: no injury, no over-exercising and no obvious incident that triggered it?
These are the kinds of questions that could point towards rheumatoid arthritis, a painful and frustrating condition that affects about 700,000 people in the UK.
Rheumatoid arthritis (RA) is an autoimmune disease in which the body’s immune system mistakenly attacks the lining of its own joints (the synovium), causing inflammation, pain and – if left untreated – lasting damage. Though most often associated with smaller joints like the knuckles and fingers, it can affect other larger joints like the knees, too.
So what are the hallmarks of rheumatoid arthritis in the knee joints – as opposed to, say, osteoarthritis? RA has certain characteristics that distinguish it from other painful knee conditions. Here are six potential indicators…
Rheumatoid arthritis: 7 signs to look out for
Swelling but no injury
This is the symptom we hinted at above. If you hurt your knee badly in a fall, you might expect to see some swelling over the next few days. If it’s swollen but you haven’t hurt it, something else is going on. Rheumatoid arthritis essentially attacks the synovial lining of the knees, causing it to become inflamed. The synovial tissues thicken (“pannus”) and release excess synovial fluid (the lubricating liquid that helps the joint to move smoothly and comfortably).
Warm and red
A swollen knee that’s also hot and red is another potential sign of rheumatoid arthritis. In RA, the soft tissues go into protection mode to fend off the “attack”, releasing inflammatory cells into the joint as well as extra fluid. The blood vessels also widen to increase blood flow to the area. This makes the knee feel hot and tender to the touch. (It’s worth noting that heat and redness are also symptoms of infection; it’s very important to rule this out if you do experience these symptoms.)
Pain in both knees
The most common type of arthritis – osteoarthritis (OA) – is a wear-and-tear condition, where the cartilage on bone endings becomes depleted, increasing friction within the joint. That kind of damage rarely occurs in equal measure. Usually, it affects one of your knees first, especially if the alignment of your leg is putting extra strain on that knee. Since RA is an autoimmune problem, the damage can happen simultaneously. So pain and swelling that is “symmetrical” – ie affects both knees at once – is another red flag for rheumatoid arthritis.
Worse in the mornings
When we see patients with rheumatoid arthritis, they often tell us the pain and stiffness is worse in the mornings, right after they get out of bed. Typically, the stiffness lingers for at least half and hour. That contrasts with osteoarthritis, where the symptoms tend to disappear more rapidly. “Morning stiffness that is a symptom of osteoarthritis usually wears off within 30 minutes of getting up,” explains the NHS, “but morning stiffness in rheumatoid arthritis often lasts longer than this.”
Worse after rest (not just after activity)
For similar reasons, activity doesn’t necessarily trigger rheumatoid stiffness in the same way as osteoarthritis. In OA, activity increases friction, which increases pain. By contrast, in rheumatoid arthritis, inflammatory cells and fluid accumulate within the joint space even as you rest. So when you get up (or wake up) and start moving again, the pain and stiffness can actually feel worse than it did while you were active.
Involving other joints too
Again, it’s helpful here to contrast rheumatoid arthritis with the wear-and-tear type. Osteoarthritis damage has a focal point – a specific joint or portion of the joint where the cartilage has worn away and left the bone ending exposed, triggering your symptoms. Because rheumatoid arthritis is a systemic (body-wide) condition, it can flare up in multiple places at once, in potentially wide-ranging ways. The symptoms can include more general problems like sweating, high temperature, dry eyes and lack of energy. On which note…
Feeling tired and unwell
A general feeling of fatigue and unwellness is another potential sign of rheumatoid arthritis. Patients often liken it to having the flu; you feel exhausted, your limbs feel heavy and hard to move, you lack energy even if you seemed to sleep well the night before. The reasons why this happens can be varied and complex: everything from anaemia and certain medicines to missed meals, stress and the constant grind of living with ongoing pain may be involved. But if you’re feeling fatigue alongside any of the other symptoms above, it’s another good reason to seek advice from an expert.
Support for rheumatoid arthritis
The number of people in the UK who suffer from rheumatoid arthritis has been increasing in recent years. Fortunately, there’s a lot we can do to manage the situation. If you’re concerned that your knees are being affected by RA, it’s a good idea to get yourself checked out. We can take a look at the problem, organise tests and scans to rule out other conditions, and refer you to a rheumatology specialist if necessary. To book an appointment, hop to our Contact page – or you can call or email the team and they’ll help you take the next steps.

