Low blood pressure or hypotension is characterized by blood pressure so low that it becomes difficult for the blood to supply oxygen and nutrients to vital organs like the heart, brain, and kidneys. This can result in organ dysfunction or complete failure.
The autonomic nervous system controls involuntary actions of the smooth muscles, heart, and glands. Besides factors like volume, thickness, heart rate, and resistance of blood vessels, it is the autonomic nervous system that determines how the circulatory system responds.
Low blood pressure is primarily defined by the symptoms of a low flow of blood instead of a specific number, as is in the case of a high blood pressure. Some people with a low blood pressure reading continue to function normally without showing any signs of distress. On the contrary, people who normally have high blood pressure start showing signs even on a moderate fall in blood pressure.
Low blood pressure can cause various problems:
- If there is an insufficient supply of blood to the brain, it causes giddiness, confusion, or fainting.
- Insufficient blood supply to coronary arteries is liable to cause chest pain as the heart muscles do not getting enough blood to function properly.
- Similarly, reduction of blood supply to the kidneys hinders the elimination of wastes, increasing toxicity.
- While standing, blood tends to settle in the lower limbs and lower blood pressure. If a person already has low blood pressure, it is likely to drop further when changing from a sitting or lying position to a standing position. Sudden dizziness or fainting in such instances is indicative of a low blood pressure.
- A persistently low blood pressure may lead to shock, a life-threatening condition.
In healthy individuals who do not show any symptoms of low blood pressure and no signs of organ damage, low blood pressure does not need any treatment. Identification of the cause behind low blood pressure, however, is necessary for treatment.
Dehydration is one of the common conditions that causes low blood pressure. Mild dehydration due to diarrhea and vomiting can be easily managed at home with oral fluids. Dehydration may also be due to extreme cases of natural remedies for high blood pressure like a weight loss program that requires vigorous exercise. Too much sweating during exercise or sporting activities can sometimes cause severe dehydration requiring hospitalization and intravenous injection of fluids and electrolytes.
Blood loss due to an internal or external injury can cause a reduction in the volume the blood, and ultimately lead to low blood pressure. Continuous bleeding needs to be attended for immediate resolution.
Sometimes high blood pressure medications like diuretics and beta blockers may cause symptoms of low blood pressure. Modifying the dose or changing the drug allows blood pressure to revert to normal.
Either an abnormally slow heart beat (bradycardia) or rapid heart beat (tachycardia) can also cause reduction in blood pressure. Bradycardia is treated by an implantable pacemaker and tachycardia with oral medications, catheterization, and/or implants.
Blood pressure is one of the important vital signs of overall health. Most instances of low blood pressure are not viewed as medical conditions, but when accompanied by symptoms, must be evaluated by a physician. Negligence in this respect can in some instances prove to be disastrous.