The major sign of hypoventilation is:
In hypoventilation the amount of air moving in and out of lungs is reduced. Hypoventilation results in hypoxia (reduced oxygen availability to cells), hypercapnia (increased CO2 content of blood), dyspnoea (difficulty in breathing) and death. Hypercapnia (sign) stimulates respiratory centre excessively and leads to dyspnoea (symptom).
Cyanosis
Dyspnoea
Hypercapnia
Hypoxia