<unk>  (forced respiration) is increased volume of air during breathing. It can occur with or without an increase in respiration rate. It is characterized by deep breathing. It may be physiologic—as when required to meet metabolic demand of body tissues (for example, during or after exercise, or when the body lacks oxygen at high altitude or as a result of anemia)—or it may be pathologic, as when sepsis is severe.<unk>  is further characterized by the required use of muscle contraction during both inspiration and expiration. Thus,<unk>  is active breathing as opposed to the passive process of normal expiration.<unk>  is distinguished from tachypnea, which is a respiratory rate greater than normal, resulting in rapid and shallow breaths.<unk>  is also distinguished from hyperventilation, which is over-ventilation (an increase in minute ventilation), which involves an increase in volume and respiration rate, resulting in rapid and deep breaths.
Hyperpnea
Apnea
Tachypnea
Cornea
Orthopnea
Labored breathing
Hypopnea
Platypnea