– an excessive amount of blood in a body part
1. Active or Arterial Hyperemia
– due to an increased arterial supply
Physiological active hyperemia
– supplies increased nourishment to organs or tissues doing increased work
b. Pathological active hyperemia
– initiates inflammation and forms one of the most important features of inflammation
2. Passive or Venous Hyperemia
– due to decreased venous drainage or a blockage
– always pathological
Local
– usually due to an obstruction of a vein by a thrombus or embolus, thickening of the vessel wall, or pressure from an outside lesion such as a neoplasm or enlarged organ
– may lead to local edema
b. Generalized
– the flow of blood through the lungs is often reduced
– may lead to anasarca
– therefore, less blood is oxygenated
– usually due to a heart disorder
– anoxemia
– less oxygen is in the tissues
– hypoxia
– leading to shortness of breath
– and a bluish discoloration of the skin, lips, nail beds and mucous membranes
– dyspnea
– cyanosis