Based on your symptoms, my best guess would be osteoarthritis (or perhaps some other type of arthritis). I know you are young and this is typically a condition that begins in the middle-aged years, but some young people have been known to get arthritis as well. If anyone in your family has joint problems, you may have a predisposition towards it. Also, you can get this condition early in life from overuse or abuse of the joints from sports. If you were very active, even as a child in a sport that required a lot of jumping (such as cheerleading, for example) this could cause it. Another possible cause of knee and hip pain or early onset arthritis is overweight.

My hubby developed sudden knee pain and went through a battery of tests including x-rays and MRI. The doctors and therapist discussed several possibilities including a torn or damaged meniscus (due to a fall) and arthritis, along with an upper thigh band (can't recall the medical term, but it's the one that supports the knee) which was tight and needed to be stretched. The general consensus was arthritis. Hubby went through physical therapy and is losing weight currently. His knee still bothers him occasionally, but it seems to be much improved. As far as what you describe as the pain coming and going -- being bad sometimes and better sometimes -- that does indeed go along with arthritis.

If you haven't already had a medical work-up done, I would get that under way.

I have the same situation. Although arthritis can contribute it is most likely iliotibial band syndrome [ITBS] or lateral collateral ligament issues. Im alances in your hip musculature is often the culprit i have gotten relief from hip stretching and strengthning the quadriceps. Using a knee brace can help but relying on them creates an environment that cause weakness over time. Stretching your gastrocnemius and soles will help too. Research the web for exercises and stretching routines. Look up information on the pigeon pose used in yoga. Good luck, some days will be better than others.