Does diclofenac retain water? Understanding the Link to Fluid Retention

October 11, 2025 •

2 min read

According to prescribing information from the FDA, fluid retention and edema have been observed in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) like diclofenac. This article explores the pharmacological mechanism behind the question, 'Does diclofenac retain water?' and provides crucial information on managing this potential side effect.

Quick Summary

Diclofenac, like other NSAIDs, can cause fluid retention and swelling, primarily by affecting kidney function and sodium balance. The risk is heightened in individuals with pre-existing heart or kidney conditions. Symptoms include swelling and weight gain.

Key Points

Diclofenac causes water retention by inhibiting prostaglandins in the kidneys, which reduces blood flow and increases sodium and water reabsorption.
Swelling (edema) in the arms and legs is a common symptom, along with rapid weight gain.
Patients with pre-existing conditions like heart failure, kidney disease, or hypertension are at higher risk for severe fluid retention from diclofenac.
Oral diclofenac carries a greater risk of fluid retention than topical formulations like gels, due to lower systemic absorption.
Management includes consulting a doctor, reducing dietary sodium, elevating swollen limbs, and considering alternative pain relief options.
Diclofenac can interfere with blood pressure medications, making them less effective at controlling fluid balance.
For mild cases, stopping the medication under a doctor's supervision often resolves the issue.

Understanding Diclofenac and Fluid Retention

Diclofenac is an NSAID used to reduce pain and inflammation. A known side effect of NSAIDs, including diclofenac, is fluid retention, or edema. While often mild, it can be serious for those with pre-existing heart or kidney conditions.

How Diclofenac Causes Water Retention

Diclofenac inhibits COX enzymes, which produce prostaglandins. Prostaglandins help regulate kidney function and blood flow. By blocking COX enzymes, diclofenac reduces prostaglandins, leading to decreased kidney blood flow, increased sodium and water reabsorption, and interference with diuretics. This results in increased body fluid and swelling, particularly in the extremities.

Who Is at Risk for Diclofenac-Induced Edema?

Certain individuals face a higher risk of fluid retention from diclofenac. Risk factors include pre-existing heart conditions (heart failure, hypertension), kidney or liver disease, older age, high dosage, and long-term use.

Managing and Mitigating Diclofenac-Related Edema

Consult your doctor if you experience fluid retention. Management strategies include communicating with your doctor, reducing dietary sodium, elevating swollen limbs, using compression garments, and gentle exercise.

Diclofenac vs. Other NSAIDs for Fluid Retention Risk

While all NSAIDs pose a risk of fluid retention, the risk profile can vary.


NSAID (Example Brand)	Primary Use	Potential for Fluid Retention	Cardiovascular Risk Profile	Notes
Diclofenac (Voltaren)	Pain, inflammation	Moderate to High	Relatively High	May have a higher overall risk compared to some alternatives.
Ibuprofen (Advil, Motrin)	Pain, fever, inflammation	Moderate	Increased risk of stroke	Common OTC option, but still carries fluid retention risk.
Naproxen (Aleve)	Pain, inflammation	Moderate	May be lower than other non-aspirin NSAIDs	Often suggested as a potentially "heart-safer" NSAID.
Celecoxib (Celebrex)	Pain, inflammation	Lower (COX-2 selective)	Increased risk with high doses	A selective COX-2 inhibitor, may have a different side effect profile than non-selective NSAIDs.

Alternative Pain Relief Options

Alternatives to NSAIDs include acetaminophen, topical diclofenac gel, physical therapy, and weight management. Some natural supplements like omega-3s, curcumin, and green tea may help, but consult a healthcare provider. A good resource for additional research is the National Institutes of Health (NIH).

Conclusion: The Final Word on Diclofenac and Water Retention

Diclofenac can cause water retention by affecting kidney function. While often mild, it can be risky for those with underlying health conditions. Recognize symptoms and consult a healthcare provider to weigh benefits and risks, or consider alternatives.

Final Word

Understanding the potential for fluid retention is crucial. Always follow medical instructions, monitor for swelling or weight gain, and seek medical advice for concerns, especially with pre-existing conditions.

Frequently Asked Questions

Yes, diclofenac can cause swelling, or edema, in the legs and ankles. This is a potential side effect that results from the medication causing the body to retain more fluid.

Diclofenac, as an NSAID, inhibits cyclooxygenase (COX) enzymes, which in turn reduces the production of kidney-regulating prostaglandins. This leads to decreased renal blood flow and increased reabsorption of sodium and water.

Individuals with a history of heart failure, kidney disease, liver disease, or hypertension should be especially cautious. Older adults are also at a higher risk.

Diclofenac gel has lower systemic absorption compared to oral tablets, meaning less of the medication reaches the bloodstream. This makes fluid retention less likely with topical application, but it is not entirely eliminated as a risk.

Contact your healthcare provider immediately. They may recommend stopping the medication, adjusting the dose, or exploring alternative treatments. Do not make changes to your medication without medical advice.

Mild swelling can often be managed with strategies like elevating swollen limbs and reducing dietary sodium. However, these steps should be discussed with your doctor to ensure they are safe and appropriate for your health.

Alternatives include non-NSAID pain relievers like acetaminophen, though it does not treat inflammation. Topical diclofenac gel is also an option with lower risk. Non-drug therapies like physical therapy are also available.