When we talk about renal function, the ability of your kidneys to filter waste, balance fluids, and regulate essential chemicals in your blood. Also known as kidney function, it’s not just about peeing—it’s about keeping your whole body running smoothly. Your kidneys filter about 120 to 150 quarts of blood every day, pulling out waste and extra fluid to make about 1 to 2 quarts of urine. If renal function drops even a little, toxins build up, blood pressure spikes, and your bones and heart start to suffer.
That’s why doctors keep an eye on two key numbers: creatinine, a waste product from muscle breakdown that healthy kidneys clear out, and eGFR, the estimated glomerular filtration rate that tells you how well your kidneys are filtering. A normal eGFR is above 90. Below 60 for three months or more means chronic kidney disease. And yes, it can sneak up on you—many people have no symptoms until it’s advanced. High blood pressure, diabetes, and long-term use of certain painkillers or antibiotics are the usual suspects. Even dehydration, especially in older adults or during illness, can temporarily crash renal function.
Some of the posts below show how drugs like fluoroquinolones and macrolides can stress your kidneys, or how antibiotics might cause liver injury that also affects kidney health. Others dig into how diabetes and hormone imbalances mess with fluid balance and kidney filtration. You’ll find real talk on when to worry about rising creatinine, what eGFR numbers actually mean for your daily life, and how meds like metformin or lithium need careful dosing if your kidneys aren’t at 100%. There’s no fluff here—just what you need to know to spot trouble, ask the right questions, and protect your kidneys before it’s too late.
Metformin and contrast dye were once thought to dangerously interact, raising lactic acidosis risk. New guidelines show the risk is extremely low for most patients-especially with normal kidney function. Here’s what you really need to know.
