Low blood pressure or hypotension refers to the fall in blood pressure below normal. It is a condition in which the action of the heart, in forcing the blood through the arteries, is weak. This may be a direct outcome of a weakened and devitalized system. While the normal limits are defined by the World Health Organisation as 140 mm / gh systolic and 90 mm/gh diastolic, it has now been reduced to 120 mm/gh systolic and 80 mm/gh diastolic in the US. Anything above that is high blood pressure or hypertension. Anything below is the low blood pressure.
The patient with chronic low blood pressure may complain of lethargy, weakness, fatigue, and dizziness. The patient may faint, especially if arterial pressure is lowered further when he assumes an erect position. These symptoms are presumably due to a decrease in perfusion of blood to brain, heart, skeletal muscle and other organs
The most important cause of low blood pressure is faulty nutrition .It makes the tissues forming the walls of the blood vessels over relaxed, and flabby or stretched. This results in less supply of oxygen and nutrients to the tissues. Malnutrition can result from a diet deficient in calories, proteins, vitamin C, or almost any one of he B vitamins. Sometimes the blood pressure falls rapidly because of loss of blood. Low blood pressure may also develop gradually because of slow bleeding in the gastrointestinal tract, kidneys, or bladder. Emotional problems are a far more frequent cause of low blood pressure. To a laser degree, prolonged disappointments and frustration may result in a subnormal blood pressure.