Low Blood Pressure (Hypotension)

What are the causes of low blood pressure?

Conditions that reduce the volume of blood, reduce cardiac output (the amount of blood pumped by the heart), and medications are frequent reasons for low blood pressure.

  • Dehydration is common among patients with prolonged nausea, vomiting, diarrhea, or excessive exercise which shunts blood away from the organs to the muscles. Large amounts of water are lost when vomiting and with diarrhea, especially if the person does not drink adequate amounts of fluid to replace the depleted water.

    Other causes of dehydration include exercise, sweating, fever, and heat exhaustion, or heat stroke. Individuals with mild dehydration may experience only thirst and dry mouth. Moderate to severe dehydration may cause orthostatic hypotension (manifested by lightheadedness, dizziness, or fainting upon standing). Prolonged and severe dehydration can lead to shock, kidney failure, confusion, acidosis (too much acid in the blood), coma, and even death.
  • Moderate or severe bleeding can quickly deplete an individual's body of blood, leading to low blood pressure or orthostatic hypotension. Bleeding can result from trauma, surgical complications, or from gastrointestinal abnormalities such as ulcers, tumors, or diverticulosis. Occasionally, the bleeding may be so severe and rapid (for example, bleeding from a ruptured aortic aneurysm) that it causes shock and death rapidly.
  • Severe inflammation of organs inside the body such as acute pancreatitis can cause low blood pressure. In acute pancreatitis, fluid leaves the blood vessels to enter the inflamed tissues around the pancreas as well as the abdominal cavity, concentrating blood and reducing its volume.
Reviewed on 7/14/2014

STAY INFORMED

Get the Latest health and medical information delivered direct to your inbox!