Joint pain in the knees after a viral fever is usually due to temporary joint inflammation during recovery. Rest the joints, use a warm compress, do gentle movements to avoid stiffness, and stay well hydrated to help with healing. Eat nutritious food, avoid heavy activity, and gradually return to a normal routine as pain improves. If the pain is severe, persistent, or limits walking, consult a doctor to determine the cause and guide appropriate care.

Osteoarthritis can cause severe knee pain, stiffness, swelling, cracking sounds, difficulty walking and reduced joint movement because the protective cartilage inside the knee slowly wears down over time. Pain may worsen with climbing stairs, prolonged standing, excess body weight, cold weather, or increased physical activity. Pain-relieving and anti-inflammatory medicines may help reduce knee pain and swelling temporarily, depending on age, stomach health, kidney function, blood pressure, and other medical conditions. Some people may also benefit from joint-support medicines, calcium, vitamin D, physiotherapy, hot compresses, knee braces, and muscle-strengthening exercises for better long-term relief. Weight control, avoiding excessive stair climbing, and regular low-impact exercise, such as walking or jogging, may also help reduce pressure on the knee joints. In advanced osteoarthritis, injections or knee replacement surgery may sometimes be considered if daily activities become very difficult. Avoid frequent self-use of painkillers because long-term use may affect the stomach, kidneys, or heart. Seek medical advice if swelling becomes severe, the knee suddenly locks, fever appears, or walking becomes increasingly difficult.