Obesity Hypoventilation Syndrome - Signs and Symptoms

Signs and Symptoms

Most people with obesity hypoventilation syndrome have concurrent obstructive sleep apnea, a condition characterized by snoring, brief episodes of apnea (cessation of breathing) during the night, interrupted sleep and excessive daytime sleepiness. In OHS, sleepiness may be worsened by elevated blood levels of carbon dioxide, which causes drowsiness ("CO₂ narcosis"). Other symptoms present in both conditions are depression, and hypertension (high blood pressure) that is difficult to control with medication. The high carbon dioxide can also cause headaches, which tend to be worse in the morning.

The low oxygen level leads to excessive strain on the right side of the heart, known as cor pulmonale. Symptoms of this disorder occur because the heart has difficulty pumping blood from the body through the lungs. Fluid may therefore accumulate in the skin of the legs in the form of edema (swelling), and in the abdominal cavity in the form of ascites; decreased exercise tolerance and exertional chest pain may occur. On physical examination, characteristic findings are the presence of a raised jugular venous pressure, a palpable parasternal heave, a heart murmur due to blood leaking through the tricuspid valve, hepatomegaly (an enlarged liver), ascites and leg edema. Cor pulmonale occurs in about a third of all people with OHS.