before my meniscal tear was trimmed (on the inside of my knee)........
i had pain on a v deep squat, or any yoga positiion that combined a deep bend with a twist of the knee.
I had pain doing breast stroke or kikcking off from the wall if I did not kick straight against the wall
the pain was generally sharp, unpleasant and not something I liked to do.... but it generally did not effect running or biking......
however.
if its torn, then the area thats torn is essentially non functional - the meniscus acts as a shock absorber. if its compromised then the rest of the knee / cartlage on the end of the bones is taking the impact.
I ended up with damaged cartilage - essentailly OA.
I used to get the feeling of a tight knee following long or hard runs - due to swelling but this would go down in a day or so. It would also tighten up after sitting following the above, or the following night. it would loosen up quickly - ie after walking 20 yards to get a coffee.
If i ran on it again it felt a lot better - so i did not worry.
i found 3-4 months of consistent training also brought it on - ie 'damage' accummulated to where i would notice it more often. / consistently. Add a fast half marathon and that took me a week to get over
At that point lying in bed at night became v. uncomfortable. I needed a pillow under it to prevent it being straight.
All of the above happened / took 2 years to progress.
I don't know which issue caused which symptom, but I think the root cause was a rugby injury 20 years ago. add 10 years of increasing running volume and intensity and oops!
however I had also had an issue / pain from the other knee 3 years ago. I went so far as to getting an mri on the nhs. However that took so long that by then rest and doing gym work etc resulted in it just going away.
dont despair as it might not be that serious.
i would recommend seeing a physio - good one should have a pretty good idea if its meniscal. A crap physio will have no idea. The one I saw was linked to a professional football team so had seen plenty over the years.
finally an mri will show it up. again if you need a trim, find the best person you can. If you are nhs it will take a while. GPs are generally useless on this - I got 'sorted' in about 4 weeks going private, (on company private health ins)
not sure if any of that helps but it was fun / theraputic to write