What is the term for the absence or deficiency of blood in a particular area?

The term that describes the absence or deficiency of blood in a particular area is ischemia. Ischemia occurs when there is a reduction in blood flow, often due to blockage of blood vessels, which can lead to tissue damage and dysfunction because the affected area does not receive adequate oxygen and nutrients that are typically delivered by the blood.

This condition is particularly significant in medical contexts as it can result in severe issues such as pain, organ dysfunction, or even tissue death. Ischemia may also be temporary or chronic, depending on the underlying cause and duration of reduced blood flow.

In contrast, hyperemia refers to an increased blood flow to a particular area, which is the opposite of what is being asked. Anemia is a condition characterized by a deficiency in the number or quality of red blood cells in the entire body, affecting overall oxygen transport but not localized blood flow. Hypoxemia indicates a deficiency of oxygen in the blood, which can be a consequence of various factors, including ischemia, but it does not specifically refer to the absence of blood in a particular area.