Keeping your kidneys healthy comes down to a handful of everyday habits: staying hydrated, managing blood pressure and blood sugar, eating a balanced diet, and avoiding substances that strain your kidneys over time. Most kidney damage develops gradually and silently, so the choices you make now have an outsized effect on how well your kidneys function decades from now.
How Much Water Your Kidneys Need
Water helps your kidneys flush waste products and excess minerals out through urine. When you’re consistently dehydrated, your kidneys have to work harder to concentrate urine, which can contribute to kidney stones and, over time, reduced function.
The general target for healthy adults is 11.5 to 15.5 cups (2.7 to 3.7 liters) of total fluid per day, including water from food and other beverages. That range is wide because your needs shift based on your body size, how much you sweat, and where you live. Hot or humid weather, high altitudes, and exercise all increase fluid loss, so you need to drink more to compensate. A simple check: if your urine is pale yellow, you’re likely getting enough. Dark yellow or amber-colored urine is a signal to drink more.
Keep Blood Pressure Under 130/80
High blood pressure is one of the two leading causes of kidney disease, alongside diabetes. Your kidneys are packed with tiny blood vessels that filter your blood. When pressure in those vessels stays elevated, it damages the filtering units over time, reducing their ability to remove waste.
The 2025 guidelines from the American Heart Association and American College of Cardiology set a treatment goal of below 130/80 mm Hg for all adults. For people who already have early kidney disease with protein leaking into the urine, specific blood pressure medications that block a hormone system called RAAS are recommended because they slow kidney damage on top of lowering pressure. But even if your kidneys are perfectly healthy right now, keeping blood pressure in range is one of the most effective things you can do to protect them long-term.
Regular physical activity, limiting sodium, maintaining a healthy weight, and moderating alcohol intake are all proven ways to lower blood pressure without medication. If lifestyle changes aren’t enough, medication can close the gap.
Blood Sugar and Your Kidneys
Chronically elevated blood sugar damages the small blood vessels in the kidneys the same way it damages vessels in the eyes and feet. Over years, this leads to diabetic kidney disease, which is the single most common cause of kidney failure worldwide.
If you have diabetes, keeping your hemoglobin A1c (a measure of average blood sugar over three months) in an individualized target range, generally between 6.5% and 8%, significantly reduces the risk of kidney complications. The exact target depends on your age, how long you’ve had diabetes, and other health factors. If you don’t have diabetes but carry risk factors like obesity or a family history, getting your fasting blood sugar checked regularly catches problems early, when they’re easiest to manage.
A Kidney-Friendly Eating Pattern
The DASH diet (Dietary Approaches to Stop Hypertension) is one of the most studied eating patterns for protecting the kidneys. It emphasizes fruits, vegetables, whole grains, lean meats, fish, poultry, nuts, seeds, legumes, and low-fat dairy, while limiting sweets, red meat, and saturated fat. In clinical studies, a reduced-sodium version of the DASH diet lowered nighttime blood pressure by about 5 mm Hg in people with moderate kidney disease, without causing dangerous shifts in potassium or other electrolytes.
Beyond blood pressure, DASH improves cholesterol, insulin sensitivity, and heart disease risk, all of which matter because heart disease and kidney disease tend to travel together. If you already have moderate or advanced kidney disease, your doctor may modify the standard DASH recommendations to limit potassium, phosphorus, or protein, since damaged kidneys can’t clear these as efficiently.
Watching Protein Intake
Protein is essential, but excess protein creates more waste products that your kidneys have to filter. For people with healthy kidneys, a normal balanced diet isn’t a concern. However, very high-protein diets sustained over years may increase the workload on your kidneys. For people already diagnosed with kidney disease who aren’t on dialysis, the recommended range drops to about 0.6 to 0.75 grams of protein per kilogram of body weight per day. For a 170-pound person, that translates to roughly 46 to 58 grams of protein daily, well below what many people consume.
Sodium Matters More Than You Think
Excess sodium raises blood pressure and forces your kidneys to retain more water. Most adults consume far more sodium than needed, largely from processed and restaurant foods rather than the salt shaker. Aiming for under 2,300 mg per day (about one teaspoon of table salt) is a reasonable target, and closer to 1,500 mg offers additional benefit for blood pressure.
Medications and Supplements That Can Harm Kidneys
Common over-the-counter painkillers like ibuprofen and naproxen (NSAIDs) reduce kidney blood flow by blocking the production of compounds called prostaglandins that keep the kidney’s blood vessels dilated. Occasional use in a healthy person is generally fine, but regular use, especially in people who are dehydrated, older, or already have reduced kidney function, can cause real damage. Acetaminophen (Tylenol) is generally easier on the kidneys for routine pain relief, though it carries its own risks for the liver at high doses.
Herbal supplements are a less obvious threat. Several herbs have been directly linked to kidney toxicity in case reports, including aristolochic acid-containing herbs (historically found in some traditional Chinese medicine products), thundergod vine, tribulus, St. John’s wort, and wormwood. On the dietary supplement side, excess vitamin A, vitamin C, and vitamin D have all been associated with kidney injury, as have creatine, chromium, hydrazine, and glucosamine in certain cases. Star fruit is specifically dangerous for people who already have kidney disease. The broader issue is that supplements aren’t regulated the way medications are, so contamination and mislabeling add additional risk.
How to Know If Your Kidneys Are Healthy
Kidney disease rarely causes noticeable symptoms until it’s advanced, which is why screening matters. Two simple tests capture most of the picture. The first is an eGFR (estimated glomerular filtration rate), a blood test that estimates how efficiently your kidneys are filtering. A normal eGFR is 90 or above. Values between 60 and 89 can indicate mild decline. Below 60 signals moderate to severe kidney disease, and below 15 is considered kidney failure.
The second is a urine albumin-to-creatinine ratio (uACR), which checks for protein leaking into your urine. A normal result is less than 30 mg/g. Values above that threshold suggest the kidney’s filtering barrier is damaged, sometimes years before eGFR begins to drop. Together, these two tests catch kidney problems early enough to slow or stop progression.
If you have high blood pressure, diabetes, a family history of kidney disease, or you’re over 60, ask for both tests at your next routine lab work. For healthy adults without risk factors, these tests are typically part of standard bloodwork and urinalysis during periodic checkups.
Exercise and Weight Management
Regular physical activity lowers blood pressure, improves insulin sensitivity, and helps maintain a healthy weight, all of which protect your kidneys indirectly. Obesity itself is an independent risk factor for kidney disease. Excess body fat increases the filtering demand on each kidney and promotes inflammation that damages kidney tissue over time. Even modest weight loss in people who are overweight can improve blood pressure, blood sugar, and markers of kidney function.
You don’t need an intense regimen. Consistent moderate activity, like brisk walking for 30 minutes most days, delivers meaningful cardiovascular and metabolic benefits that translate directly to kidney protection.