The discomfort but no pain in the right knee may be caused by cartilage damage, meniscus injury, physiological reasons such as excessive exercise and other factors. 1. Cartilage damage: due to trauma and other factors, resulting in cartilage damage in the knee joint, the degree of damage is mild, resulting in pain performance is not obvious but discomfort symptoms, the need for timely MRI examination. 2. Meniscus injury: due to sports such as basketball, resulting in meniscus injury, there are different degrees of tearing, which can cause discomfort in the knee. 3. Physiological reasons: If you lack exercise in general and suddenly engage in strenuous exercise such as long-distance running or mountain climbing, the pressure on your knees is greater, resulting in discomfort symptoms, which can be relieved after rest or physical therapy. If the symptoms persist, it is necessary to go to the hospital in time, the specific cause and treatment according to the doctor’s instructions.