Some painkillers, particularly nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen, can affect kidney function in susceptible people. Risk may be higher with prolonged use, dehydration, older age, or existing kidney disease.
People should not assume that medicines sold without a prescription are always harmless. If they have kidney problems or take multiple medications, they should ask a doctor or pharmacist which products are suitable.
Why kidney disease may remain hidden
The kidneys have considerable functional reserve. A person can lose a significant amount of kidney function before obvious symptoms appear.
When symptoms do develop, they may include:
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Swelling around the ankles, feet, or face.
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Persistent tiredness or weakness.
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Changes in urination.
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Poor appetite or nausea.
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Muscle cramps.
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Difficulty concentrating.
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Persistent itching.
These symptoms are not specific to kidney disease and can have many other causes. A person should not diagnose kidney failure based on a single symptom.
An illustrative medical consultation showing the importance of routine health checks.
Which tests can detect kidney problems?
Two common tests are particularly useful.
The first is a blood test measuring creatinine, which can be used to estimate the glomerular filtration rate, commonly called eGFR. This helps healthcare professionals assess how effectively the kidneys are filtering blood.
The second is a urine test measuring albumin. Albumin is a protein that can leak into the urine when the kidney's filtering structures are damaged. The urine albumin-to-creatinine ratio is commonly used to assess this.
Doctors may repeat these tests over time because one abnormal result does not always establish chronic kidney disease. The duration and pattern of abnormalities matter.
People with diabetes, high blood pressure, cardiovascular disease, a family history of kidney disease, or previous kidney injury should discuss appropriate screening with their healthcare professional.
The most important lesson is that kidney disease should be investigated through proper testing. A photograph of a man in a hospital chair and a cup of coffee cannot identify the cause of his condition.
Chapter 5: How to Drink Coffee More Wisely and Protect Your Kidneys
Coffee does not need to disappear from everyone's daily routine simply because kidney disease is a serious health condition. For many people, moderate consumption of plain coffee can fit into a balanced lifestyle.
However, the right amount depends on individual health, caffeine sensitivity, blood pressure, medications, and kidney function.
A review published in Nephrology Dialysis Transplantation in 2026 concluded that moderate coffee consumption appears generally safe for most people with chronic kidney disease. It also emphasized that excessive intake should be avoided, particularly in people experiencing insomnia, anxiety, palpitations, or poorly controlled blood pressure.
Here are practical steps that can help.
Choose simpler coffee drinks
Plain black coffee contains relatively little phosphorus, sodium, calories, carbohydrates, and protein. The National Kidney Foundation notes that these components are minimal in black coffee, although potassium still needs consideration for some people.
National Kidney Foundation
If you enjoy sweetened coffee, consider gradually reducing the amount of sugar or flavored syrup. This can help lower added sugar and calorie intake without requiring you to abandon coffee completely.
Be careful with powdered creamers
People with kidney disease should pay attention to the ingredients in creamers and powdered coffee mixes. Some contain phosphate additives that may be important for people who need to limit phosphorus.
Check the ingredient list and ask a renal dietitian whether a particular product is suitable for your dietary plan.
Avoid excessive caffeine
The US Food and Drug Administration commonly cites 400 milligrams of caffeine per day as an amount not generally associated with dangerous effects for most healthy adults. However, this is not a target everyone should aim to reach, and individual sensitivity varies.
People who experience palpitations, anxiety, high blood pressure, or sleep problems may need less. Pregnant individuals and people taking certain medications may also require different advice.
Do not use coffee as a replacement for water
Coffee contributes to fluid intake, but it should not become the only drink throughout the day. Water remains an appropriate everyday choice for many people.
However, people with advanced kidney disease or heart failure may have specific fluid restrictions. They should follow their prescribed allowance rather than automatically increasing water intake.
Build habits that protect kidney health
Coffee is only one small part of a much larger health picture. Protecting the kidneys involves several habits:
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Keep blood pressure within the target range recommended by your doctor.
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Manage blood glucose if you have diabetes.
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Avoid smoking.
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Maintain a healthy weight where possible.
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Eat a balanced diet with appropriate sodium intake.
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Stay physically active according to your abilities.
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Avoid unnecessary or prolonged use of potentially harmful medicines.
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Attend kidney screening when recommended.
People who already have chronic kidney disease should not copy another person's diet without medical advice. Their potassium, phosphorus, sodium, and fluid requirements may be very different from those of a healthy adult.