Tissue perfusion is the amount of blood flowing through a tissue per unit of time. Inadequate tissue perfusion is an insufficient blood supply to a tissue locality or organ. Strictly speaking, it is a symptom of insufficient effective circulating blood volume in the body circulation, or microcirculatory disorders, due to a variety of causes. Microcirculatory disorders are morphological abnormalities and dysfunctions of blood vessels and blood flow that occur at the microcirculatory level. Microcirculatory disorders can lead to a significant reduction in tissue blood perfusion, which can cause a range of ischemic and hypoxic lesions and, in severe cases, organ insufficiency or failure.