Hyperventilation: Overbreathing. Hyperventilation causes dizziness, lightheadedness, a sense of unsteadiness, and tingling around the mouth and fingertips. Hyperventilation can be severe enough to mimic the early warning symptoms of a heart attack, and is therefore a common cause of emergency room visits in the US. Hyperventilation is common and normal after aerobic exercise. Hyperventilation can be caused by serious diseases of metabolism and anxiety. Relief for hyperventilation caused by anxiety can be achieved by breathing in and out of a paper bag to increase the level of carbon dioxide in the blood.