Hello, and welcome to our community!  Sorry to hear you are having a problem with your knee. There are many, many things that can cause pain in and around your knee.  There are muscles and ligaments than can be strained, and then there is also the possibility of arthritis. Did you injure your knee, or did it just start hurting?  I have OA in both knees and walking upstairs can be a challenge at times.  One of my knees makes a "crunching" sound when I walk up the stairs because the bone is rubbing against bone. Do you have anything like that?

Since there are so many different things that could be causing your pain, you really need to see a doctor. He/she will do a physical examination and will probably do xrays. The doctor may suggest some sort of anti-inflammatory medicine, ice or heat, and perhaps physical therapy.  Please let us know what your doctor says and how you are doing.

Best Wishes,

V