It'll gradually go down. You can also push on it, sometimes it helps with mine. Depends on how fast it can drain. Sometimes an ibuprofen helps. They don't last but you'll get flare ups.

They sometimes comes about due to a lack of lubrication or damage to the knee within the joint so the body produces its own, if that makes sense.

I had one when I had a torn meniscus. They can and do go down on their own but inflams will also help, as will rest.

Its worth while keeping an eye on it, as as I said they can be a sign of damage to the joint or other health issues.

Saying that I'm not a doc, just what I was told by my doc when I had the knee op.

I would think I would know if I had a torn meniscus due to severe knee pain. I have no joint pain, so I am confused why this happened--so weird.

Thats where you could possibly be wrong, a torn meniscus can be there without any pain. They can come about via wear and tear.

Anyhow I'm not saying thats what you have, what I'm saying is get it fully checked, don't ignore it. The only way to be certain is by having an MRI.

Interesting... and a bummer. Always thought there would be pain with a tear.
thanks for your insight

I had one and it resulted because of very recent torn meniscus in knee that I did not realize I had until I went in for MRI.