What is the most common cause of respiratory acidosis?

Respiratory acidosis occurs when there is an inhalation of carbon dioxide that leads to an increase in carbonic acid in the blood, resulting in lowered blood pH. The most common cause of respiratory acidosis is hypoventilation, which is insufficient ventilation that prevents adequate exchange of gases in the lungs. This can happen when the respiratory rate is too low or when the depth of breathing is inadequate to fully expel carbon dioxide.

In cases of hypoventilation, the body retains carbon dioxide, leading to an accumulation of carbonic acid. The body attempts to compensate for this chemical imbalance, but if the hypoventilation persists, it results in significant acidemia (increased acidity in the blood).

Other potential causes of respiratory acidosis, such as airway obstruction or pulmonary embolism, may also lead to similar effects, but they are less commonly the direct underlying mechanisms compared to hypoventilation, particularly in clinical scenarios involving chronic respiratory conditions or central nervous system depressants.