Picture this. It’s the middle of the night. Most people are fast asleep. But some people wake up on purpose, just to drink a glass of water. Then they go right back to bed. It sounds strange. But for people who keep getting kidney stones, this small habit can make a big difference.Kidney stones are painful. Anyone who has had one knows that. But here’s the part that surprises many people. Having one stone often isn’t the end of the story. For a lot of patients, it’s just the beginning.Once a stone, always a stoneDr Ankur Bhatnagar, a senior urologist at Sarvodaya Hospital in Faridabad, sees this pattern all the time in his clinic. He says, “It’s very right that once a stone former, always a stone former.” That’s not just a saying. It’s backed by numbers. As he explains, “Up to 50 percent of our patients who have undergone surgery for kidney stones or have had stones in the past, will have a recurrence within the next 5 to 10 years.” A study published in 2025 had also found that kidney stones have a recurrence risk of 30–50% within five years, with surgical recurrence often being the most clinically significant and burdensome.That number stops a lot of people in their tracks. Half of all patients. Within just a few years. So why does this keep happening, even to people who eat well and try to live healthy?The hidden problem doctors look forThe answer, says Dr Bhatnagar, usually lies deep inside the body, in things we can’t see or feel. “The most important thing is the underlying metabolic abnormality has not been corrected,” he explains. In simple words, something in the body’s chemistry is still off. And unless that gets fixed, new stones can keep forming.Sometimes the cause is something as basic as water. If someone wasn’t drinking enough before, and still isn’t, stones will likely return. Other times, the body is doing something on its own that leads to trouble. Some people pass too much calcium out through their urine, a condition called hypercalciuria. Others don’t have enough citrate in their urine, and citrate normally helps stop stones from forming. Dr Bhatnagar adds that these problems don’t just go away on their own. “The patient continues to have that,” he says.There’s a simple way to get answers, though. If a person has passed a stone or had one removed, doctors can test it. “That can be analyzed to see what is the composition of the stone which gives us some clue to give the patient some medications to prevent recurrence,” Dr Bhatnagar says. On top of that, a 24-hour urine test and some blood work can reveal exactly what’s going wrong, whether it’s too much calcium, too little citrate, high oxalate, or high uric acid.And it isn’t always about body chemistry. Sometimes the kidney or the tube leading out of it, called the ureter, has a shape problem. Dr Bhatnagar points to conditions like a calyceal diverticulum or a blockage where the kidney meets the ureter. Urine gets stuck instead of flowing freely, and stones start to form. Infections can cause the same kind of trouble too, and in those cases, treating the infection is the real fix. His advice for anyone dealing with repeat stones is simple. “Do talk to your urologist if you have recurrent kidney stones,” he says.The daily habits that keep stones awayOnce the medical cause is found, prevention often comes down to everyday choices. And water sits right at the top of the list. Dr Bhatnagar recommends spacing it out through the day rather than gulping it all at once. He suggests starting the day with about half a liter first thing in the morning, then sipping 150 to 200 ml every hour after that, and drinking another half a liter before bed. That’s also where the midnight glass of water comes in. If sleep breaks in the middle of the night, he suggests having a glass or two before drifting off again.Food matters just as much. Fruits and vegetables, especially citrus fruits, help lower the risk, and Dr Bhatnagar wants to clear up a common myth around them. “There are certain notions that tomatoes and spinach increase the incidence, there is nothing of that sort,” he says. Cutting back on salt matters too, especially packaged foods, which tend to be loaded with it. Eating less meat also helps, since it makes urine more acidic, which encourages stones to form.For people managing diabetes or extra weight, keeping both under control plays a role as well. None of these steps are complicated on their own. But together, they can be the difference between one kidney stone and a lifetime of them.
