Your kidneys filter about half a cup of blood every minute, removing waste, balancing minerals like sodium and potassium, and helping regulate blood pressure. Supporting them comes down to a handful of daily habits: staying hydrated, managing blood pressure and blood sugar, eating reasonable amounts of sodium and protein, being careful with certain medications and supplements, and staying physically active.
What Your Kidneys Actually Do
Beyond filtering waste, your kidneys maintain the balance of water, salts, and minerals in your blood. They remove excess acid produced by your cells. They also produce hormones that help control blood pressure, stimulate red blood cell production, and keep bones strong. When kidney function declines, all of these systems start to suffer, often without obvious symptoms until significant damage has occurred.
Two numbers give you a snapshot of kidney health. Your eGFR (estimated glomerular filtration rate) measures how well your kidneys filter blood: 60 or higher is normal. A urine albumin test measures protein leaking into your urine: below 30 is normal, while above 30 can signal early kidney stress. These are worth knowing if you have risk factors like high blood pressure or diabetes, and they’re part of routine bloodwork your doctor can order.
Keep Blood Pressure in Check
High blood pressure is one of the most common causes of kidney damage, and the mechanism is straightforward. Your kidneys contain tiny filtering units with delicate blood vessels. Normally, your body adjusts blood flow so that pressure spikes don’t reach those fragile capillaries. But when blood pressure stays elevated over time, this protective system gets overwhelmed. The specialized cells lining your kidney filters, which have limited ability to repair themselves, start to break down under the sustained force. That leads to scarring that progressively reduces your kidneys’ filtering capacity.
The tricky part is that once kidney damage begins, it impairs the kidneys’ ability to protect themselves from further pressure-related injury. The threshold for damage drops lower and lower, creating a cycle where even moderately elevated blood pressure causes accelerating harm. This is why keeping blood pressure well controlled, rather than just “close enough,” matters so much for long-term kidney health. Regular cardiovascular exercise, limiting sodium, maintaining a healthy weight, and taking prescribed blood pressure medications consistently are the most effective strategies.
Manage Blood Sugar Before It Causes Damage
Chronically elevated blood sugar damages kidneys through multiple pathways at once. Excess glucose in the blood reacts with proteins and other molecules in kidney tissue, creating compounds called advanced glycation end products. These stiffen and thicken the filtering membranes, reduce tissue flexibility through crosslinking with collagen, and trigger inflammation. At the same time, high glucose activates several chemical pathways inside kidney cells that generate harmful reactive molecules, compounding the injury.
The result is a gradual thickening of the kidney’s basement membranes and an accumulation of scar-like tissue that crowds out healthy filtering structures. This process can unfold over years without symptoms. If you have diabetes or prediabetes, tight blood sugar control is one of the most impactful things you can do for your kidneys. If you don’t have diabetes, maintaining a healthy weight and staying active are your best defenses against developing it.
Stay Hydrated, but Don’t Overthink It
Water helps your kidneys flush waste products efficiently. The general guideline for healthy adults is 11.5 to 15.5 cups (2.7 to 3.7 liters) of total fluid per day from all sources, including food. That range comes from Mayo Clinic recommendations and covers most people under normal conditions. You’ll need more if you exercise heavily, live in a hot climate, or are recovering from illness.
You don’t need to obsessively track ounces. Pale yellow urine generally signals adequate hydration. Dark yellow or amber-colored urine means you should drink more. The goal is consistent, moderate hydration throughout the day rather than large volumes all at once.
Watch Your Sodium Intake
The 2020-2025 Dietary Guidelines for Americans recommend no more than 2,300 milligrams of sodium per day. For context, a single teaspoon of table salt contains about 2,300 mg, and most Americans regularly exceed this limit through processed and restaurant foods. Excess sodium forces your kidneys to retain more water to maintain the right concentration in your blood, which raises blood pressure and increases the workload on your filtering units over time.
The biggest sources are rarely the salt shaker. Bread, deli meats, canned soups, frozen meals, cheese, and condiments account for most dietary sodium. Reading nutrition labels and cooking more meals at home are the most practical ways to stay within range.
Rethink Your Protein Habits
Protein is essential, but eating large amounts creates more work for your kidneys. When your body breaks down protein, it produces acids and waste products that your kidneys must filter out. Animal-based proteins like red meat tend to produce more of these acids than plant-based sources.
The 2025-2030 Dietary Guidelines suggest adults eat 1.2 to 1.6 grams of protein per kilogram of body weight per day. For a 150-pound person, that works out to roughly 82 to 109 grams daily. High-protein diets that push well beyond this range may also increase inflammation and oxidative stress, making it harder for your kidneys to function at their best. This is especially important if you already have reduced kidney function, where the extra load falls on a system that’s already compromised. Shifting some of your protein intake from animal to plant sources (beans, lentils, tofu, nuts) can reduce the acid burden on your kidneys while still meeting your nutritional needs.
Be Cautious With OTC Painkillers
Nonsteroidal anti-inflammatory drugs, commonly known as NSAIDs, include ibuprofen (Advil, Motrin) and naproxen (Aleve). These medications work by blocking the production of certain chemical signals called prostaglandins. The problem is that those same signals help keep blood vessels in your kidneys dilated, maintaining adequate blood flow to your filtering units. When NSAIDs block that dilation, blood flow to the kidneys drops and filtration rate decreases.
Occasional use in a healthy person is generally fine. The risk rises with frequent or long-term use, dehydration, older age, or pre-existing kidney issues. If you rely on NSAIDs regularly for pain, it’s worth discussing alternatives with your healthcare provider.
Think Twice About Supplements
The supplement industry is loosely regulated, and several common products have documented associations with kidney injury. The spectrum of harm ranges from kidney stones to acute kidney injury and, in severe cases, chronic kidney disease. Herbal supplements linked to kidney damage include St. John’s wort, tribulus, wormwood, and thundergod vine. On the non-herbal side, creatine, glucosamine, chromium, and excessive doses of vitamins A, C, and D have all appeared in case reports of kidney toxicity.
Star fruit is specifically dangerous for people who already have chronic kidney disease. The safest approach is to treat supplements with the same scrutiny you’d give a medication: assume they have real physiological effects (because they do) and verify that they’re safe for your situation before taking them long-term.
Move Your Body Regularly
Aerobic exercise benefits your kidneys through several mechanisms. It helps regulate the nervous system activity that controls blood vessel tone in the kidneys, potentially relaxing the vessels that carry blood away from the filtering units. Exercise also increases blood flow through the kidneys, improving the health of blood vessel linings and reducing oxidative stress that can lead to progressive scarring.
A meta-analysis of studies involving patients with existing kidney disease found that roughly 35 weeks of aerobic training improved kidney filtration rate by about 2 ml/min compared to standard care, while also improving cardiovascular fitness and modestly reducing BMI. That filtration improvement may sound small, but in the context of a disease where function typically only declines, even stabilization is meaningful. For people with healthy kidneys, regular exercise helps protect against the two biggest threats to kidney health: high blood pressure and diabetes. Aim for at least 150 minutes of moderate aerobic activity per week, whether that’s brisk walking, cycling, swimming, or whatever you’ll actually stick with.