Long standing inflammation at the point where the plantar fascia attaches to the heel sometimes causes calcification. This can eventually build up to form a heel spur which can be see on x-ray as a “bony” lump on the under side of the heel bone. 

Not surprisingly this situation can become painful as the spur digs into the surrounding soft tissues and causes further inflammation.  I vicious circle exists.  Pain in the plantar fascia associated with these spurs can be treated with podiatry by trying to cushion the effected area and spreading the load.  Some people benefit from using an orthotic device.