Your GFR (glomerular filtration rate) measures how well your kidneys filter waste from your blood, and a normal reading is 90 or above. If your number has dropped, several strategies can slow further decline and, in some cases, help it recover: managing blood pressure, adjusting what you eat, losing excess weight, staying hydrated, and avoiding medications that stress the kidneys. How much improvement is possible depends on whether the damage is recent and reversible or part of a longer-term pattern.
What Your GFR Number Actually Means
GFR is estimated from a blood test, most commonly using creatinine (a waste product from muscle metabolism) along with your age and sex. A more accurate version adds a second marker called cystatin C. Neither method gives a perfect measurement. The result is an estimate, and it becomes less precise at higher levels. That means a single low reading doesn’t necessarily confirm kidney disease, especially if you were dehydrated, sick, or had recently eaten a large amount of protein when the blood was drawn.
The stages of chronic kidney disease are defined by GFR ranges. A GFR of 60 to 89 is considered mildly decreased, 45 to 59 is mild-to-moderate, 30 to 44 is moderate-to-severe, 15 to 29 is severe, and below 15 is kidney failure. Importantly, a GFR of 60 to 89 by itself doesn’t qualify as kidney disease unless there’s other evidence of damage, such as protein in your urine. So if your number landed in this range and you’re otherwise healthy, it may not be as alarming as it looks on paper.
Manage Blood Pressure First
High blood pressure is one of the top two causes of kidney decline (along with diabetes), and controlling it is the single most effective way to protect your GFR over time. A class of blood pressure medications that block the hormone angiotensin II is particularly important for kidney protection. These drugs work by relaxing the small blood vessel on the outflow side of the kidney’s filtering units, which lowers the pressure inside each filter. That reduced pressure means less wear and tear on the delicate filtering membranes.
When you first start one of these medications, your GFR may actually dip slightly. This is expected and generally not a sign of harm. It reflects the drop in filtering pressure, which is protective in the long run. Your doctor will monitor your blood work in the first few weeks to make sure the dip stays within a safe range.
A newer class of medications originally designed for type 2 diabetes (SGLT2 inhibitors) has also shown strong kidney-protective effects. These drugs cause an initial average GFR decline of about 3.5 points, but after roughly six months, the GFR trajectory stabilizes and the long-term rate of decline slows significantly. About 37% of patients in one large study experienced no GFR decline at all. These medications are now prescribed specifically for kidney protection even in people without diabetes.
Eat Less Protein, and Choose Plant Sources
Protein creates waste products that your kidneys must filter out, so eating large amounts of it forces your kidneys to work harder. For people with established kidney disease who want to slow GFR loss, guidelines from major kidney organizations recommend reducing protein intake to 0.6 to 0.8 grams per kilogram of body weight per day. For a 170-pound person, that works out to roughly 46 to 62 grams of protein daily, which is less than most Americans typically eat.
The type of protein matters too. Animal protein (from meat, poultry, and dairy) triggers a measurable spike in glomerular filtration pressure. This effect has been documented since the 1920s and has been confirmed repeatedly since: animal protein elevates GFR acutely, increases protein leakage into urine, and accelerates kidney function decline over time. Plant-based protein does not produce the same hyperfiltration response and is consistently associated with better kidney outcomes. You don’t need to go fully vegetarian, but shifting the balance toward beans, lentils, tofu, and nuts can meaningfully reduce the filtering burden on your kidneys.
Cut Sodium to Reduce Kidney Stress
High sodium intake raises blood pressure and increases the workload on your kidneys. The National Kidney Foundation recommends that people with kidney disease or high blood pressure aim for no more than 1,500 mg of sodium per day. For context, a single fast-food meal can easily exceed that amount. The general population guideline is 2,300 mg, so if you’re starting from a typical American diet (which averages over 3,400 mg), any reduction helps. Reading labels, cooking at home more often, and choosing fresh over processed foods are the most practical ways to get there.
Lose Weight If You Carry Excess
Obesity forces the kidneys into overdrive. In people with significant excess weight, cardiac output and GFR both rise by roughly 25%, and total blood flow to the kidneys increases substantially. This state, called hyperfiltration, looks like a high GFR number on a lab test but actually represents damage in progress. It’s like an engine revving too high: the output looks impressive, but the parts wear out faster.
Weight loss partially reverses this. After losing an average of about 58 pounds in one study, participants saw their inflated GFR, renal blood flow, and kidney volume all come back down toward normal. For people whose GFR was already below 120 (meaning they weren’t hyperfiltrating), weight loss was associated with a GFR increase. So depending on your starting point, losing weight can either bring a dangerously high GFR down to a safer level or nudge a low GFR upward.
Stay Properly Hydrated
Dehydration can make your GFR look worse than it actually is. In a study of healthy adults, GFR measured nearly 20% higher when participants were in a low-hydration state compared to a high-hydration state at baseline. That sounds backward, but it reflects how the kidneys concentrate urine when fluid is scarce. Chronic mild dehydration, on the other hand, can genuinely stress the kidneys over time.
The practical takeaway: drink enough water that your urine stays pale yellow. If you’re about to have your GFR tested, consistent hydration in the days before the blood draw will give you a more accurate reading. Overhydrating right before the test won’t artificially boost your number, but showing up dehydrated can distort it in either direction.
Avoid Medications That Harm the Kidneys
Common over-the-counter painkillers like ibuprofen and naproxen (NSAIDs) can cause acute drops in GFR, especially in people who already have reduced kidney function. These drugs work by constricting blood vessels in the kidney, which reduces blood flow to the filtering units. Occasional use in a healthy person is generally fine, but regular use in someone with a GFR below 60 is risky. People with kidney disease are often exposed to NSAIDs through a combination of prescription and over-the-counter use without realizing the cumulative effect. Acetaminophen (Tylenol) is typically a safer alternative for pain relief when kidney function is a concern.
Correct Metabolic Acidosis
As kidney function drops, the blood can become slightly too acidic, a condition called metabolic acidosis. This creates a cycle where the acidity itself accelerates further kidney damage. Oral sodium bicarbonate (essentially baking soda in tablet form, prescribed by a doctor) can break this cycle. In a five-year study of patients with early kidney disease from high blood pressure, daily sodium bicarbonate preserved GFR significantly better than placebo. The benefit appeared even in patients whose blood acid levels hadn’t yet reached the threshold for a formal acidosis diagnosis, suggesting that early correction may be more protective than waiting for obvious lab abnormalities.
GFR Recovery After Acute Injury
If your GFR dropped suddenly due to an acute event (a severe infection, a reaction to medication, surgery complications, or a period of very low blood pressure), recovery is often possible. In a large study of nearly 48,000 patients with moderate to severe acute kidney injury, 61% recovered kidney function within four days, and another 22% recovered within ten days. A smaller group took up to three months. The speed of recovery matters for long-term outlook: faster recovery is associated with a lower risk of permanent kidney function loss down the road.
This is very different from the gradual GFR decline seen in chronic kidney disease, where the goal shifts from recovery to slowing the rate of loss. If your GFR dropped because of a specific, identifiable cause that has since been resolved, there’s a reasonable chance your numbers will climb back toward baseline over weeks to months.