Why Does Your Knee Hurt Going Down Stairs (But Not Up)?
Descending stairs loads the kneecap with several times your body weight while the quadriceps works to control the drop. That combination makes downhill and downstairs pain a classic sign of patellofemoral pain syndrome, one of the most common knee complaints in active adults.
Other causes can produce a similar pattern, including cartilage softening behind the kneecap, early arthritis, or irritation of the tendon below it. The distinctions matter because the treatments differ, and guessing wrong can prolong the problem.
Most patellofemoral pain improves with targeted strengthening of the hips and quadriceps rather than rest alone. If pain persists beyond a few weeks, involves swelling, or follows an injury, an evaluation can pinpoint the cause and match you with the right plan.