Medically reviewed by Grant Hughes, MD If you experience knee pain after sitting with your legs bent, it may be caused by arthritis, tendonitis, bursitis, or patellofemoral pain. If your knees hurt ...

Knee pain at night is a common condition caused by injury, arthritis, bursitis, gout, and more. When it happens at bedtime, it can also lead to insomnia , which can leave you exhausted during the day.