opportunistic infection - any infection caused by a microorganism that does not normally cause disease in humans; occurs in persons with abnormally functioning immune systems (as AIDS patients or transplant patients receiving immunosuppressive drugs)
Why your 'flushing' could be a red alert to see your doctor. It is a normal body response that may occur when we are embarrassed, angry, excited, or experiencing other strong emotions. But 'flushing' - when the face, ears, neck and, occasionally, upper chest, take on a red colour, accompanied by a hot feeling - can also be a sign of a more serious underlying condition.
Your second floor toilet is often referred to as a phantom flusher. You think it has flushed because you here the toilet tank filling with water. No ghosts or goblins flushed the toilet. The ball cock valve in the tank turned itself on because the water level in the tank dropped.