<P> Blood pressure is influenced by cardiac output, total peripheral resistance and arterial stiffness and varies depending on situation, emotional state, activity, and relative health / disease states . In the short term it is regulated by baroreceptors which act via the brain to influence nervous and endocrine systems . </P> <P> Blood pressure that is low due to a disease state is called hypotension, and pressure that is consistently high is hypertension . Both have many causes and may be of sudden onset or of long duration . Long term hypertension is a risk factor for many diseases, including heart disease, stroke and kidney failure . Long term hypertension is more common than long term hypotension . Long term hypertension often goes undetected because of infrequent monitoring and the absence of symptoms . </P> <Table> Classification of blood pressure for adults <Tr> <Th> </Th> <Th> systolic, mmHg </Th> <Th> diastolic, mmHg </Th> </Tr> <Tr> <Td> Hypotension </Td> <Td> <90 </Td> <Td> <60 </Td> </Tr> <Tr> <Td> Desired </Td> <Td> 90--119 90--129 </Td> <Td> 60--79 60--84 </Td> </Tr> <Tr> <Td> Prehypertension (high normal) </Td> <Td> 120--139 130--139 </Td> <Td> 80--89 85--89 </Td> </Tr> <Tr> <Td> Stage 1 hypertension </Td> <Td> 140--159 </Td> <Td> 90--99 </Td> </Tr> <Tr> <Td> Stage 2 hypertension </Td> <Td> 160--179 </Td> <Td> 100--109 </Td> </Tr> <Tr> <Td> Hypertensive urgency </Td> <Td> ≥ 180 </Td> <Td> ≥ 110 </Td> </Tr> <Tr> <Td> Isolated systolic hypertension </Td> <Td> ≥ 160 </Td> <Td> <90 </Td> </Tr> </Table> <Tr> <Th> </Th> <Th> systolic, mmHg </Th> <Th> diastolic, mmHg </Th> </Tr>

Which term is used to describe a blood pressure of 90 mm hg systolic and 50 mm hg diastolic