Low blood pressure is more of a physiological condition than a disease. In medicine, and particularly physiology, hypotension refers to a condition of abnormally low blood pressure in the systemic circulation and the arteries. Medical terms for low blood pressure is hypotension which can be classified into postprandial hypotension, neutrally mediated hypotension (NMH) and orthostatic hypotension. Hypotension is numerically blood pressure that is lower than 90/60.
The body blood pressure is indicated as by two numbers. The first number represents the systolic pressure which is a term for pressure that exists in the arteries the moment the heart beats and it gets filled with blood. The lower number measures diastolic pressure which is that pressure that exists in the arteries between the beats that is when the heart rests. Optimal low blood pressure is any reading below 120/80.
Low blood pressure or hypotension in the normal sense is not a health concern especially if it is not accompanied with any symptoms and need not be treated. However, low blood pressure can be a sign of a hidden physiological problem especially if it occurs in old people. Hypotension commonly leads to less blood flow to the brain, heart and other vital organs.
The risk of hypotension and even high blood pressure increases with age largely due to changes that occur as one ages. Close to 30 percent of people aged above 65 experience postural hypotension. When bloods pressure suddenly drops, the brain is deprived of vital oxygen and nutrients from the blood that it will need to function properly by the second. This will lead to lightheadedness or a prolonged dizziness. These sudden slumps in blood pressure are common when the affected individual is rising from a sitting or sleeping position. This is what is called orthostatic hypotension or postural hypotension. When the patient stands for very long, then neutrally mediated hypotension can result. Postural hypotension on the other hand is a failure of the nervous or cardiovascular system to react to sudden body changes.