Arthritic knee swells up like a balloon after a long walk. Is fluid on the knee a bad sign and can they drain it?

Six months into taking my right knee seriously and mostly doing well thanks to the advice on here. Walk split into two loops, cushioned trainers, physio exercises most days. But something new. Did a longer walk on Saturday, about five miles with my son, and by the evening the knee had swollen up properly. Puffy all round the kneecap, tight, couldn't bend it fully, and if I press on one side I can feel the fluid move to the other. Like a water balloon.

It's gone down a lot by today but not completely. No redness, no temperature, not especially hot to touch. Is this fluid on the knee a sign the arthritis is getting worse fast? And my son says his mate had his knee drained with a needle and it was instant relief, is that something I should be asking for?

Mine does this if I jump up a big mileage week on the bike. Swells for a couple of days, settles. For me it's the clearest "you did too much" signal there is, more reliable than pain.

Five miles from a standing start of two loops is a big jump, Dennis. In the group we tell new people to add a bit at a time, never double it in one go. Your knee's sending you an invoice.

Feet up, ice wrapped in a towel, and an easier few days usually did it for mine.

Dennis R said:

Is this fluid on the knee a sign the arthritis is getting worse fast?

Dennis, the direct answer: swelling after a bigger than usual walk is common in knee osteoarthritis and on its own it does not mean the arthritis is accelerating. An arthritic joint produces extra fluid when it is irritated, and a sudden jump in load, such as going from your usual loops to five miles, is one of the commonest triggers. Cyclelou and Sue have it right: a knee that swells after a big day and settles over a few days is a dosage signal. The response is to build distance up more gradually, not to stop walking. Swelling that comes and goes is one of the recognised symptoms of knee osteoarthritis, and building distance up in small steps is how you keep walking without provoking it.

On draining it: removing fluid with a needle (aspiration) is a real procedure, and it is done when a knee is very tense and painful, or when a doctor needs to examine the fluid to rule out infection or crystals such as gout. It is sometimes combined with a steroid injection during a flare. For a knee that is already going down by itself within a couple of days it is not usually needed, and the fluid tends to come back if the cause is unchanged.

The pattern that is different and needs same day medical attention: a knee that becomes hot, red and very swollen, especially with a fever or feeling unwell, or swelling that comes on without any obvious reason and does not settle. That can be infection or another inflammatory problem and should not wait. If your swelling keeps recurring after ordinary activity, it is worth mentioning to your GP or physiotherapist, who can examine it, which a forum cannot.

Had mine drained once years ago during a bad flare. Relief, yes. But it was back in about a week because I hadn't changed anything. What actually stopped the balloons was the pool and building up slowly.

Follow up. Went back to the two loops, added about ten minutes a week instead of doubling. No balloon since. Did four miles yesterday with only a bit of puffiness by the evening, gone this morning. The "invoice" line has become a family saying.

Mentioned it to the physio anyway. She had a feel, said the same as Mr Henderson, build it slowly, and gave me a couple of extra exercises for the thigh.