Symptoms include tingling sensation (usually in the limbs), abnormal heartbeat, painful muscle cramps, and seizures.

This explains the other common symptoms of hyperventilation—pins and needles, muscle cramps and tetany in the extremities, especially hands and feet.

Chemoreceptors in the body sense a change in partial pressures and pH (hydrogen ion concentration) in the blood.

[citation needed] Deliberate hyperventilation has been used by underwater breath-hold divers for the purpose of extending dive time as it effectively reduces respiratory drive due to low CO2 levels.

This allows one to break their standard limit of breath holding, at an increased risk of shallow water blackout (which is a significant cause of drownings).