Heat and swelling
Your brain continuously works to balance the chemicals in your body and when there is damage to any body part, chemicals are released and fluid is sent to cushion and nourish the area -- hence the heat and swelling.
This is another sign that something is not right. This is your body's way of getting your attention, and it is usually quite effective. Eventually, pain may limit your ability to get around and enjoy favorite activities. If pain prevents you from moving about or exercising, it can lead to weight gain and other health problems.
Your joints require motion to maintain function, as a certain amount of weight-bearing stress and movement is needed to nourish cartilage and prevennt bone loss. If pain prevents regular movement, the joint can deteriorate to the point of immobility.