Hypovolaemia

**Definition:** This is a state of decreased blood volume; more specifically, decrease in volume of blood plasma. It is thus the intravascular component of volume contraction (or loss of blood volume due to things such as haemorrhaging or dehydration), but, as it also is the most essential one, hypovolemia and volume contraction are sometimes used synonymously.

**Exclusions:** - Traumatic shock, not elsewhere classified - Hypovolaemic shock