Hyperventilation refers to the act of breathing fast or increasing the respiratory rate. When we breathe normally, we take about 15 to 18 breaths per minute (one breath cycle includes one inhalation and one exhalation); however when we hyperventilate we take about 18 to 20 breaths per minute, and this rate can go up to 30 breaths per minute during a panic attack.
During hyperventilation there is more oxygen in the blood than is used, and as a result not enough oxygen reaches the brain. You can find out more about breathing and learn breathing exercises to help against hyperventilation under the mindriselife tab.