Autonomic Dysfunction Causing Orthostatic Hypotension, Leading to Dizziness

Introduction

Autonomic dysfunction refers to a condition in which there is damage to the nerves of the autonomous nervous system of the body. The autonomous nervous system, which comprises the parasympathetic autonomic nervous system (PANS) and sympathetic autonomic nervous system (SANS), controls normal body functions, such as the temperature of the body, rate of breathing, heart rate, feeling of sensation, and digestion. These two systems, PANS and SANS, either slow down certain body functions or stimulate them as the situation demands.

 

Damage to the nerves of this autonomous nervous system gives rise to the condition that is termed autonomic dysfunction. This condition, in turn, can affect the autonomous nervous system in parts or completely. An improperly regulated autonomic nervous system can lead to a condition termed orthostatic hypotension.

 

Orthostatic hypotension: Definition

Orthostatic hypotension is one type of orthostatic intolerance, in which orthostatis means an upright position and hypotension refers to low blood pressure levels. Orthostatic intolerance is when a patient commonly experiences discomforting symptoms when trying to change positions of the body. These symptoms are usually feelings of dizziness and lightheadedness accompanied by nausea, fainting, and excessive sweating.

 

Symptoms of orthostatic hypotension

Orthostatic hypotension is caused by a sharp drop in blood pressure when trying to stand up. This change in position brings with it heart palpitations, lightheadedness, dizziness, nausea, weakness, blurred vision, and fainting due to a significant drop in blood pressure. Other symptoms of orthostatic hypotension include pain in the chest, dry skin owing to excessive sweating, impotence, and incontinence (i.e., an inability to hold one’s urine).

 

Causes of orthostatic hypotension

Orthostatic hypotension is primarily caused by a drop in blood pressure. Normal daily activities, such as trying to stand or get up after being seated for a long time, can also lead to dizziness. One may experience other symptoms of orthostatic hypotension as well.

 

Dehydration has also been found to be a culprit in orthostatic hypotension. Dehydration could be due to long hours in the sun or it could even be due to bleeding, vomiting, or diarrhea, all of which lower the blood volume and in turn cause dizziness. Excessive exercising can also lead to dehydration and in turn cause weakness and dizziness.

 

The older population has been found to be more susceptible to spells of dizziness, lightheadedness, and other associated symptoms caused by orthostatic hypotension. In the older generation, the likelihood of orthostatic hypotension-like symptoms is also seen commonly after meals are consumed.

 

Other causes of orthostatic hypotension include heart ailments. Orthostatic hypotension due to autonomic dysfunction is also caused due to nerves being injured or damaged because of conditions such as diabetes or Parkinson’s disease. In general, disorders of the endocrine and nervous system can also lead to orthostatic hypotension.

 

The valsalva maneuver (attempting to exhale forcefully against blocked airways), when performed during a bowel movement or unintentionally, like when clearing the throat, can also lead to dizziness. Interestingly, this maneuver is also used as a diagnostic test for dizziness.

 

These are some of the daily activities and other medical causes that lead to orthostatic hypotension-induced dizziness.