Please tell me how to get rid of right knee pain. What could be the cause?

Hello?

Knee pain that I didn't have a few days ago has developed.

The left side of my right knee hurts, as shown in the picture.

My joints hurt every time I walk.

I haven't particularly overexerted myself or fallen.

So, there are no bruising-like injuries.

But I don't know why I suddenly feel pain.

I am waiting, thinking that time will be the cure.

Is there anyone who has had a similar experience?