What organ is hard on Aleve? Understanding Naproxen's Impact on Your Body

October 8, 2025 •

4 min read

Aleve (naproxen) is a popular over-the-counter pain reliever, but like all nonsteroidal anti-inflammatory drugs (NSAIDs), it carries a risk of significant side effects. Regular or high-dose use of Aleve can be particularly hard on organs, including the stomach, kidneys, and heart. Understanding these potential dangers is crucial for safe medication use.

Quick Summary

Naproxen, the active ingredient in Aleve, can cause serious side effects involving the stomach, kidneys, and heart. Risks include gastrointestinal bleeding, kidney damage from reduced blood flow, and heightened cardiovascular events like heart attack and stroke, especially with prolonged use.

Key Points

Stomach Bleeding Risk: Aleve can cause irritation, ulcers, and severe bleeding in the stomach and intestines, especially with long-term or high-dose use.
Kidney Damage: The kidneys are particularly susceptible to NSAID side effects, with naproxen causing reduced blood flow and potential for acute or chronic kidney injury.
Cardiovascular Events: Naproxen, like most NSAIDs, increases the risk of serious cardiovascular issues, including heart attack, stroke, and high blood pressure.
Rare Liver Complications: While less common, Aleve can cause liver damage (hepatotoxicity), especially in individuals with existing liver conditions or excessive alcohol use.
Duration and Dosage Matter: To minimize harm, it is crucial to use the lowest effective dose of naproxen for the shortest duration necessary, as risks increase with longer use.
Take With Food: Always take Aleve with food to help protect your stomach lining and reduce the risk of gastrointestinal irritation and bleeding.
Consult a Professional: People with pre-existing heart, kidney, or liver disease should consult a doctor before taking Aleve due to increased risk.

The Primary Organs at Risk from Naproxen (Aleve)

Naproxen, sold under the brand name Aleve, is a nonsteroidal anti-inflammatory drug (NSAID) that works by blocking cyclooxygenase (COX) enzymes to reduce pain and inflammation. While effective, this mechanism also impacts other bodily functions, particularly in several key organs. The most notable concerns involve the stomach, kidneys, and cardiovascular system.

The Stomach and Gastrointestinal Tract

For many individuals, the most immediate and common negative impact of Aleve is on the stomach and gastrointestinal (GI) tract. The same prostaglandins that NSAIDs block to reduce inflammation also play a vital role in protecting the stomach's mucosal lining from its own digestive acids. By inhibiting COX-1 and COX-2 enzymes, naproxen leaves the stomach lining vulnerable to irritation and damage.

Serious gastrointestinal side effects can range from mild heartburn and upset stomach to severe issues like stomach ulcers, bleeding, and perforation. The risk of these complications increases with higher doses and longer durations of use. Certain populations, such as the elderly or those with a history of ulcers, are at an even higher risk. The FDA has mandated a "black box" warning on all NSAIDs regarding this serious GI risk.

The Kidneys

Long-term or high-dose use of Aleve can also strain the kidneys. The kidneys require prostaglandins to maintain normal blood flow, especially during periods of stress, such as dehydration. When naproxen inhibits prostaglandin synthesis, it can reduce blood flow to the kidneys, leading to decreased kidney function over time. This effect can be particularly dangerous for individuals with pre-existing kidney disease, diabetes, or those who are elderly.

Potential kidney-related problems include fluid retention and elevated blood pressure, which further strains the kidneys. The use of naproxen can also trigger acute kidney injury (AKI), a sudden decline in function, and in severe cases, progressive chronic kidney disease (CKD). While damage can sometimes be reversed by stopping the medication, severe cases may lead to the need for dialysis.

The Heart and Cardiovascular System

All NSAIDs, with the exception of low-dose aspirin, carry a risk of serious cardiovascular thrombotic events. Naproxen is no exception, and the FDA requires a "black box" warning for this risk as well. This includes an increased risk of heart attack and stroke, especially with prolonged use and higher doses. The mechanism involves the alteration of substances in the blood that can lead to blood clots. Furthermore, naproxen can cause the body to retain extra fluid, which can increase blood pressure and worsen heart failure. Patients with existing heart conditions should be especially cautious and discuss NSAID use with a healthcare provider.

The Liver

While rarer than GI or kidney issues, liver damage (hepatotoxicity) is a potential side effect of naproxen. This can range from mild, asymptomatic elevation of liver enzymes to more severe drug-induced liver injury, though such severe cases are uncommon. Symptoms of liver issues can include jaundice (yellowing of the skin or eyes) and abdominal pain. Patients with pre-existing liver disease or who consume large amounts of alcohol are at a higher risk.

How Naproxen (Aleve) Compares to Other NSAIDs

It is important to understand how Aleve compares to other common NSAIDs regarding organ risk profiles. While some studies suggest naproxen might have a comparatively lower heart risk than ibuprofen at certain doses, definitive proof is lacking, and an FDA advisory panel has maintained the general cardiovascular warning for all non-aspirin NSAIDs.


NSAID	Active Ingredient	Primary Organ Concern(s)	Key Risks	Notes
Aleve	Naproxen	Stomach, Kidneys, Heart	GI bleeding/ulcers, kidney damage, heart attack, stroke	Potentially lower cardiovascular risk profile at certain doses, but not definitively proven safer.
Advil, Motrin	Ibuprofen	Stomach, Kidneys, Heart	GI bleeding/ulcers, kidney damage, heart attack, stroke	Widely used, but carries similar risks to naproxen, especially with long-term or high-dose use.
Aspirin	Acetylsalicylic acid	Stomach	GI bleeding/ulcers	Different cardiovascular profile; beneficial for heart health in low doses but high doses pose GI risk.
Tylenol	Acetaminophen	Liver	Liver damage	Not an NSAID. Does not pose the same GI or cardiovascular risks as NSAIDs but can cause liver damage, especially in high doses or with alcohol.

Minimizing Risks When Taking Aleve

Safe usage is paramount to avoid serious side effects associated with Aleve and other NSAIDs. Following these guidelines can help reduce the strain on your body's organs:

Use the lowest effective dose for the shortest duration possible. Long-term, high-dose use is associated with the highest risk of adverse effects.
Take with food. To protect your stomach lining, always take naproxen with a meal or a glass of milk.
Stay hydrated. Drinking plenty of fluids helps support healthy kidney function.
Monitor your body. Pay attention to symptoms like severe stomach pain, black or tarry stools, swelling in your ankles, or decreased urination. If you notice any of these, stop taking the medication and contact a doctor immediately.
Discuss with a doctor. If you have pre-existing conditions like heart disease, kidney disease, or a history of ulcers, consult a healthcare professional before starting naproxen.

For more detailed information on safe medication use for kidney health, refer to authoritative sources like the National Kidney Foundation's guide: Safe Medicine Use with Chronic Kidney Disease.

Conclusion

While Aleve offers effective relief for pain and inflammation, it is not without risk, particularly to the stomach, kidneys, and heart. Like all NSAIDs, it can cause gastrointestinal issues, reduce kidney function, and increase cardiovascular event risk, especially with long-term or high-dose use. By understanding these potential side effects and practicing safe usage, individuals can mitigate these risks. As always, it is essential to consult a healthcare professional to determine if naproxen is the right choice for your needs, considering your overall health and medical history.

Frequently Asked Questions

Yes, while rare, naproxen (Aleve) can cause liver damage. This risk is higher with long-term use, high doses, or for individuals with pre-existing liver disease or those who consume alcohol heavily.

Yes, Aleve can cause kidney problems, including reduced blood flow, fluid retention, and in severe cases, acute kidney injury or chronic kidney damage. This is especially true for long-term use or in vulnerable individuals.

Yes, the FDA has issued a "black box" warning for NSAIDs like naproxen (Aleve) due to an increased risk of serious cardiovascular thrombotic events, such as heart attack and stroke. The risk increases with higher doses and longer use.

Signs of stomach bleeding from Aleve include severe stomach pain, black or tarry stools, vomiting blood or material resembling coffee grounds, and feeling faint. Seek immediate medical attention if these occur.

To protect your stomach, always take Aleve with food or milk and use the lowest effective dose for the shortest period of time. Limiting alcohol intake is also advised.

Individuals with a history of stomach ulcers, gastrointestinal bleeding, significant heart disease, kidney disease, or those taking blood thinners should generally avoid Aleve or use it only under a doctor's supervision.

Kidney damage caused by NSAIDs can sometimes be reversible if the medication is stopped promptly. However, in some cases, the damage may be permanent, and continued use after injury can lead to chronic kidney disease.

Yes, Aleve can cause fluid retention and increase blood pressure, which puts a strain on the heart and kidneys. Patients with hypertension should be monitored closely.