Postural Orthostatic Tachycardia Syndrome (POTS) is a disorder involving the autonomic nervous system. When a person with POTS stands up, their body struggles to manage the gravitational shift of blood, resulting in an abnormally rapid increase in heart rate. Managing this condition often relies heavily on lifestyle adjustments, and chief among these is an aggressive strategy for fluid consumption to stabilize the cardiovascular system. This proactive approach to hydration is an important tool for reducing the lightheadedness, fatigue, and other symptoms associated with the syndrome.
The Link Between Hydration and Blood Volume
High fluid intake is recommended for individuals with POTS due to its direct effect on circulating blood volume. Many POTS patients experience hypovolemia, a deficit in plasma volume. This reduced volume makes it harder for the heart to pump enough blood back to the brain when gravity pulls blood into the lower extremities upon standing.
When the body senses this drop in circulating volume, the heart attempts to compensate by beating faster. Blood also tends to pool excessively in the legs and abdomen because the blood vessels do not constrict efficiently, further reducing the blood return to the heart. Consuming large amounts of fluid helps to expand the total volume of blood in the circulatory system.
This expansion of blood volume helps to counter both the pre-existing hypovolemia and the effects of venous pooling. By increasing the volume of fluid in the bloodstream, the heart has more to work with, allowing for better blood flow to the brain and upper body when upright. This physiological effect can mitigate the severity of symptoms like dizziness and presyncope that are triggered by standing.
Daily Fluid Intake Targets
The typical fluid intake recommendation for an adult with POTS is significantly higher than for the general population. Most medical professionals suggest aiming for a daily intake of 2 to 4 liters (approximately 67 to 135 ounces) of fluid. This target is a general guideline and should be individualized in consultation with a physician, especially for those with co-existing heart or kidney conditions.
Achieving this high volume requires a strategic approach, as simply drinking a large amount of water at once is not effective and can overwhelm the kidneys. Instead, the most beneficial strategy is consistent, small-volume sipping throughout the entire day. Many patients find it helpful to use marked water bottles or set reminders to ensure they consume a steady amount, such as 8 ounces every hour while awake.
A particularly important time for fluid intake is first thing in the morning, where consuming a large glass of fluid before rising can help combat the low blood volume that can naturally occur overnight. Daily fluid needs must also be adjusted based on environmental factors and activity levels. On hot days, or days involving exercise, the fluid target must be increased to compensate for higher sweat and fluid loss.
The Essential Role of Electrolytes and Salt
While high fluid intake is fundamental, drinking plain water alone is often insufficient and can be counterproductive for managing POTS. Consuming excessive amounts of water without adequate sodium can lead to hyponatremia, a dangerous dilution of the body’s sodium concentration. Sodium, along with other electrolytes like potassium, is the primary mechanism the body uses to retain fluid in the bloodstream.
Therefore, the aggressive hydration strategy must be coupled with a significant increase in sodium intake to make the fluids effective at expanding blood volume. Sodium helps the body hold onto the water consumed rather than quickly excreting it through urine. For many POTS patients, doctors recommend increasing daily sodium intake to a target of 3,000 to 10,000 milligrams.
Practical methods for increasing electrolyte intake include liberally adding salt to food, using salt tablets, or consuming oral rehydration solutions and electrolyte mixes. These specialized drinks contain a balanced ratio of sodium and other minerals, which facilitates more efficient fluid absorption compared to plain water or typical sports drinks. By ensuring both high fluid quantity and high electrolyte quality, individuals with POTS can maximize the therapeutic benefit of hydration.