Clinically Important Respiratory States 1.Eupnoea Normal resting respiration. 2.Hyperpnoea Increased minute volume due to increase in depth and frequency. 3.Hypopnoea Reduced minute volume due to decrease in frequency and depth of Respiration. 4.Tachypnoea Increase in respiratory frequency above the normal. 5.Bradypnoea Decrease in respiratory frequency. 6.Apnoea Temporary cessation of breathing.Asthma,lung diseases and pulmonary edema. 7.Dyspnoea Difficult and conscious breathing 8.Orthopnoea Severe dyspnoea associated with left heart failure in reclining posture, which gets relieved on sitting. 9.Asphyxia Ventilation insufficiency associated with hypoxia and hypercapnia. 10.Hypoxia Decreased Po2 in the tissue.High altitude and lung diseases are associated with hypoxia 11.Hypercapnia Increased Pco2 in the tissue. 12.Hypoxemia Low levels of O2 in the blood. 13.Hypocapnia Decreased Pco2 level in the tissue. 14.Cyanosis Bluish colouration of the skin and mucous membranes caused by the presence of reduced Hb by > (more than) 5g/100mL in arterial blood. 15.Apneusis Prolonged inspiration abruptly interrupted by very brief expiration is called apneusis.It occurs in certain types of severe brain damage.