High blood pressure, or hypertension, is a physical state in which the arterial blood pressure is elevated above the norm, which is defined as 120/80. According to MayoClinic.com, the longer that severe hypertension goes untreated, the more likely a patient is to develop serious complications such as heart attack, stroke, aneurysm and heart failure. Low blood pressure, or hypotension, can also be dangerous, though it is less common. All dangerous levels of blood pressure require medical treatment to prevent serious complications.
Abnormally Low BP
Like high blood pressure, extremely low blood pressure can also be dangerous. Very low blood pressure causes insufficient blood flow to the brain, resulting in symptoms such as lightheadedness, fainting or confusion. Systolic readings below 90, or diastolic readings below 60 would be considered abnormally low and would require treatment to help bring pressure levels back up to the normal range.
Stage 2 Hypertension
Stage 2 hypertension is defined by the American Society of Hypertension as blood pressure that is sustained between 140 to 160 systolic or 80 to 100 diastolic. A stage 2 patient, if untreated, will have significantly elevated risk of heart disease and stroke, and will show early signs of target-organ disease, such as damage to retinal blood vessels of the eyes.
Stage 3 Hypertension
Stage 3 hypertension is a dangerous state in terms of clinical outcome. ASH defines stage 3 as marked and sustained blood pressure elevations which are greater than 160 systolic or greater than 100 diastolic. This stage requires aggressive treatment with anti-hypertensive medications, as well as frequent monitoring by the patient's doctor, or serious consequences such as stroke and heart attack will result.
Malignant Hypertension
Malignant hypertension is a true medical emergency that requires inpatient hospitalization and treatment. It is characterized by a sudden and rapid rise in blood pressure, usually to greater than 200 systolic and 130 diastolic. Such a patient will often complain of chest pain and severe headache, as well as blurred vision and muscle weakness. Treatment consists of immediate hospitalization and the administering of intravenous or sublingual blood pressure medications to quickly lower the BP. Otherwise, coma and eventual death is likely to occur.
References
- NIH News: NHLBI Issues New High Blood Pressure Clinical Practice Guidelines
- American Diabetes Association: ASH Proposes New Hypertension Definition
- MayoClinic.com: Hypertension
- "Churchill's Pocketbook of Hypertension"; Isla Mackenzie et al; 2009
