Water Intake for Low Blood Pressure

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Satish R. Raj

Disqualifiers: Pregnancy

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether drinking 16 ounces of water affects blood pressure changes from morning to afternoon. It focuses on individuals with orthostatic intolerance, a condition where standing causes dizziness or lightheadedness due to a drop in blood pressure. Participants will drink water to determine if it helps stabilize their blood pressure throughout the day. This trial may suit those who frequently feel dizzy or faint when standing. As an unphased trial, it offers a unique opportunity to contribute to understanding how simple lifestyle changes might enhance daily well-being.

Do I have to stop taking my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that water intake is safe for low blood pressure?

Research has shown that drinking water is generally safe for most people. Studies have found that it can raise blood pressure in individuals with both normal and high blood pressure, indicating an effect on blood pressure. However, these studies have not reported any serious side effects from drinking water.

Water is crucial for good health, and staying hydrated is linked to better heart health and a lower risk of some health issues. While these findings suggest that water is usually well-tolerated, more research is needed to fully understand its effects on blood pressure. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike the standard treatments for low blood pressure, which often involve medications like fludrocortisone or midodrine, this approach simply uses water. Researchers are excited about this treatment because it is incredibly straightforward and involves drinking 16 ounces of water, which can rapidly increase blood volume and raise blood pressure. This method is non-invasive, has no side effects, and is easily accessible to everyone. It offers a natural and immediate way to manage low blood pressure, making it a potentially game-changing option for many people.

What evidence suggests that water intake might be an effective treatment for low blood pressure?

Research has shown that drinking water quickly can temporarily raise blood pressure. One study found that drinking water caused short-term increases in both the systolic and diastolic numbers of a blood pressure reading. Another review suggests that staying hydrated can affect blood vessel function and help manage blood pressure. However, some studies found no significant changes in blood pressure for certain groups after drinking water. Overall, water might help increase blood pressure in some cases, but results can vary.

In this trial, participants will receive 16 oz of water to evaluate its effects on low blood pressure. ^{1 5 6 7 8}

Who Is on the Research Team?

Satish R Raj, MD MSCI

Principal Investigator

Vanderbilt University

Are You a Good Fit for This Trial?

This trial is for individuals who experience orthostatic intolerance, which means they feel dizzy or lightheaded when standing up due to low blood pressure. Pregnant individuals cannot participate.

Inclusion Criteria

I feel dizzy or faint when standing up.

Exclusion Criteria

Pregnancy

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants ingest 16 oz of water to test blood pressure response

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

What Are the Treatments Tested in This Trial?

Interventions

• Water

Trial Overview The study aims to determine if drinking 16 fluid ounces of water affects blood pressure differently in the morning compared to the afternoon, challenging the belief that there's no variation.

How Is the Trial Designed?

Group I: 1 Experimental Treatment 1 Intervention

water 16 oz

Who Is Running the Clinical Trial?

Satish R. Raj

Lead Sponsor

Trials

7

Recruited

690+

Published Research Related to This Trial

Watermelon juice supplementation significantly increased plasma levels of l-citrulline, l-arginine, and nitrite, which are associated with improved nitric oxide bioavailability, but it also raised resting blood pressure compared to control conditions.

Despite the benefits in muscle oxygenation during moderate-intensity exercise, watermelon juice did not enhance time-to-exhaustion during severe-intensity exercise, suggesting it may not be effective for improving endurance performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two weeks of watermelon juice supplementation improves nitric oxide bioavailability but not endurance exercise performance in humans. Bailey, SJ., Blackwell, JR., Williams, E., et al.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11589796/

Outcomes in Randomized Clinical Trials Testing Changes ... This systematic review summarizes randomized clinical trials that tested the impact of changing participants' daily water intake on a number of health-related ...

2. nature.com nature.com/articles/s41598-025-94818-0

Impact of scheduled water intake on mild cognitive ... The results indicated that rapid water intake can lead to short-term increases in both systolic and diastolic BP and a slight reduction in HR in ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6723555/

Hydration Status and Cardiovascular Function - PMC The purpose of this review is to present the currently available evidence linking acute hypohydration with altered vascular function and BP regulation.

4. ahajournals.org ahajournals.org/doi/10.1161/JAHA.122.029645

Hemodynamic Effects of the Osmopressor Response Water bolus ingestion had no significant effects on systolic blood pressure, diastolic blood pressure or heart rate in patients with POTS in ...

5. link.springer.com link.springer.com/article/10.1007/s00421-025-05728-y

The effect of hypohydration before and different rehydration ... However, to effectively lower cardiovascular strain and core temperature following severe exercise, a rapid fluid intake would be recommended.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2908954/

Water, Hydration and Health - PMC - PubMed Central - NIH Water intake acutely reduces heart rate and increases blood pressure in both normotensive and hypertensive individuals.

7. prevention.com prevention.com/health/a69203177/can-drinking-water-lower-blood-pressure/

Does Drinking Water Lower Blood Pressure? Experts Explain Observational studies have linked habitual low water intake with blood pressure regulation challenges, but more data is needed to confirm this.

8. ahajournals.org ahajournals.org/doi/10.1161/01.cir.101.5.504

The Pressor Response to Water Drinking in Humans Background—Water drinking increases blood pressure profoundly in patients with autonomic failure and substantially in older control subjects.