<unk>  is the state of rapid breathing which results in the reduction in carbon dioxide levels (below normal) thereby leading to hypocapnia. During rapid breathing, the body loses more carbon dioxide (CO2) than it can produce resulting in net reduction of CO2 levels. This state of rapid/faster breathing is most commonly seen in stress and anxiety and termed as<unk>  syndrome. Kussmaul breathing is also a type of<unk>  and done to reduce the acidity of body as seen in metabolic acidosis.<unk>  may also be voluntarily manifested following episodes of rapid deep breathing. The symptoms of<unk>  are variable. Some patients are completely asymptomatic while others may present with minimal symptoms such as headache and numbness or tingling in the hands, feet, and lips. More severe symptoms include dizziness, lightheadedness, and fainting. Some patient also report having chest pain and slurred speech particularly when accompanied by the Valsalva maneuver. Voluntary deep breathing and induction of<unk>  is a common practice among young individuals to attain focus and adrenaline rush. Other similar terms that are completely different from<unk>  include hyperpnea and tachypnea.
Hyperpnea is commonly seen with exercise or any major physical activity as well as in response to hypoxic states. In these conditions the energy demand of the body either goes up or is not adequately met. To meet this energy deficit, the body increases the depth and rate of breathing which is known as hyperpnea. Other common examples of hyperpneic state include sepsis, anemia, and individuals living at high altitudes. Tachypnea is derived from a Greek word which means "rapid breathing". Tachypnea means rapid and shallow breathing and is also seen with exercise as a compensatory mechanism to increase the oxygen content of the body.
Hyperventilation
Hypoventilation
Permissive hypercapnia
Positive end-expiratory pressure
Enuresis
Hypnic jerk
Diuresis
Respiratory compensation