Knee pain

[wiseguy]

I have been having occasional knee pain right in the center of the knee. I first noticed it after climbing on a ladder. Every time I went up stairs or tried to run for several weeks it caused pain. This has occurred in both knees at the same time. When I run or play basketball I can sometimes stretch it out. Last night I played basketball and It hurt alot when I ran, made cuts , or landed awkwardly. Today the right knee pain is pretty intense when doing stairs especially going up stairs. Sometimes the knee seems loose. The main symptom is that it occurs while lifting the knee.
Any ideas?

Larry