The most likely causes of normal walking pain upstairs are degenerative arthritis of the knee joint, meniscus injury of the knee joint, and bursitis of the goosefoot. 1. degenerative arthritis of the knee joint: most common in the elderly, so also called senile arthritis, due to degenerative lesions of the knee joints and tissues in old age, joint pain can be seen in the early stages of the disease, with the progression of the disease can be seen in the joints of the flexion and extension of the activities and the ability to act on the decline, especially in the up and down the steps is more pronounced. 2. Knee meniscus injury: after meniscus injury, the knee joint has obvious pain, swelling and other symptoms, after the acute stage of swelling, pain subsides, but there is still pain in the joint activities, especially when going up and down the stairs, squatting, running and jumping, etc., the injury site is squeezed, the pain is more obvious. 3. Goosefoot bursitis: the main role of the three muscles of the goosefoot is to flex and internally rotate the knee joint to limit knee valgus, when inflammation occurs, the pain is severe when going up and down the stairs. Knee pain when going up the stairs, and the symptoms persist for a long time, you should go to the hospital in time for further examination, to clarify the cause of the disease, targeted treatment.