Ventilation-perfusion mismatch

Ventilation-perfusion mismatch occurs when the airflow (ventilation) to parts of the lungs doesn’t match the blood flow (perfusion) they're supposed to support. Ideally, these should be balanced so well-oxygenated air reaches blood in the lungs effectively. When there's a mismatch—either reduced airflow or blood flow—it can cause less oxygen to enter the bloodstream or less carbon dioxide to be removed, leading to breathing difficulties and inefficient oxygen delivery to the body. This imbalance is common in conditions like pneumonia or blood clots and can impair overall lung function.