Final answer:
Central venous pressure (CVP) becomes high due to conditions that increase blood volume or resistance to venous return, such as hypervolemia, heart failure, and pulmonary hypertension.
Step-by-step explanation:
Central venous pressure (CVP) is the pressure in the thoracic vena cava near the right atrium, and it indicates venous return and right ventricular function. CVP can become elevated in a variety of clinical conditions. High CVP is often associated with conditions that lead to increased blood volume or resistance to blood flow, such as hypervolemia, heart failure, pulmonary hypertension, and cardiac tamponade. High CVP can also occur during specific situations such as sepsis, where vasodilation and poor vascular tone decrease effective blood volume, prompting compensatory mechanisms that lead to hypervolemia.