What is the Difference Between Orthostatic Hypotension and POTS

The key difference between orthostatic hypotension and POTS depends on the time of diagnosis. Orthostatic hypotension is diagnosed within 3 minutes of posture change, while POTS is diagnosed within 10 minutes of posture change.

Nervous coordination plays an important role in blood pressure regulation between the upper body and the lower body. Therefore, it is important that blood pressure is regulated during posture changes to maintain the balance of the body. Physical factors like gravity and nerve impulse transmission play important roles in the regulation of blood pressure. Orthostatic hypotension and POTS are two conditions resulting from irregularities of blood pressure and nervous coordination.

CONTENTS

1. Overview and Key Difference
2. What is Orthostatic Hypotension 
3. What is POTS
4. Similarities –  Orthostatic Hypotension and POTS
5. Orthostatic Hypotension vs POTS in Tabular Form
6. Summary – Orthostatic Hypotension vs POTS

What is Orthostatic Hypotension?

Orthostatic hypotension or postural hypotension is the condition where blood pressure lowers upon changing posture from a seated or lying down position to a standing position. This may result in dizziness or lightheadedness within 3 minutes. In a usual scenario, this episode can last for a few minutes. Other common symptoms of orthostatic hypotension include blurry vision, weakness, fainting, confusion, and nausea. If there are repeated occurrences of orthostatic hypotension, the individual should report to the doctor accordingly. Blood pressure should be monitored regularly for any fluctuations under different postures.

Orthostatic hypotension happens when the natural process of counteracting low blood pressure fails. This may happen due to dehydration, heart problems, endocrine problems, nervous system disorders, and dietary imbalances. The main risk factors of blood pressure imbalances leading to orthostatic hypotension are age, various medications, diseases, alcohol, pregnancy, and prolonged sedentary behavior (bed resting). This condition may directly result in falls, stroke complications, and cardiovascular diseases.

What is POTS?

Postural orthostatic tachycardia syndrome (POTS) is regarded as a condition that affects the blood flow of an organism. Similar to orthostatic hypotension, POTS also arises when there is a posture change from a seated position to a standing position. A person is diagnosed with POTS if he/she shows symptoms of lower heart rate, lightheadedness, and dizziness within 10 minutes after a posture change. There are different types of POTS based on how the nervous and circulatory coordination varies. POTS can be Neuropathic POTS, Hyperadrenergic POTS, and Low blood volume POTS. The main reason for POTS is the loss of autonomic and sympathetic nervous system control.

The development of POTS can be due to an infection, medical complication, diet complications, alcohol, pregnancy, and/or trauma. Individuals with certain autoimmune diseases such as Sjogren’s disease are also prone to develop POTS. The main symptoms are high heart rate, high blood pressure, chest pain, chest arrest, dizziness, abdominal pain, and blurred vision. However, the time taken to show symptoms is longer than the time taken in orthostatic hypotension.

What are the Similarities Between Orthostatic Hypotension and POTS?

• Orthostatic Hypotension and POTS are two conditions related to irregularities of blood pressure.
• Both cause high blood pressure, dizziness, and lightheadedness.
• They arise due to posture changes from seated posture to standing posture.
• Both may happen due to dietary complications, lack of exercise, stress, and other infections and illnesses.
• They are also related to the lack of control of the autonomic and sympathetic nervous systems.

What is the Difference Between Orthostatic Hypotension and POTS?

Orthostatic hypotension and POTS are both related imbalances of blood pressure and lack of control in nervous coordination. However, the key difference between orthostatic hypotension and POTS is in the diagnostic criteria. In orthostatic hypotension, diagnosis takes place within 3 minutes from the posture change, while in POTS, diagnosis is taken across a time period of 10 minutes. Furthermore, the classic symptom of high pulse rate or heart rate is a unique diagnostic criterion in POTS, while orthostatic hypotension is diagnosed by low blood pressure.

The below infographic presents the differences between orthostatic hypotension and POTS in tabular form for side by side comparison.

Summary – Orthostatic Hypotension vs POTS

Orthostatic hypotension and POTS are complications arising from nervous control imbalances and blood pressure imbalances resulting from posture changes. Orthostatic hypotension is characterized by low blood pressure following posture change, while POTS is characterized by high heart rate following posture change. Furthermore, the diagnostic criteria also vary for the two conditions. Diagnosis of symptoms takes place within 3 minutes for orthostatic hypotension and within 10 minutes for POTS. So, this is the summary of the difference between orthostatic hypotension and POTS. However, symptoms and risk factors associated with both conditions are very similar.

Reference:

1. Low, P A, et al. “Comparison of the Postural Tachycardia Syndrome (POTS) with Orthostatic Hypotension Due to Autonomic Failure.” Journal of the Autonomic Nervous System, U.S. National Library of Medicine.
2. “Postural Tachycardia Syndrome (PoTS).” NHS Choices, NHS.

Image Courtesy:

1. “Orthostatic Hypertension demonstration” By RadioSmith – I filmed my friend over webcam demonstrating Orthostatic Hypotension (CC BY-SA 3.0) via Commons Wikimedia
2. “Dependent Acrocyanosis in a Norwegian 33-year old male POTS patient” By Pots Syndrome – (CC BY-SA 2.0) via Commons Wikimedia