Explainer | How your kidneys work and the best ways to take care of them

Your kidneys are responsible for a wide range of functions like regulating blood pressure and producing vitamin D. Unfortunately, we often don’t notice immediately when something’s wrong. The kidneys produce urine, but the two fist-sized organs, located on either side of the spine just below the rib cage, are about much more than that. They also regulate blood pressure, produce vitamin D and several hormones, stimulate red blood cell production, and help maintain both the body’s water and acid-base balance. In short, they’re the body’s chemical factories. If something is wrong with your kidneys, it can throw your entire body out of kilter. But how do you know if something is wrong? And how can you keep your kidneys healthy? “Unfortunately, [dysfunctional] kidneys take a very long time to make themselves felt,” says Dr Volker Lechterbeck, chief doctor in the nephrology department of Petrus Hospital in Wuppertal, Germany. The reason is that kidney disorders often aren’t accompanied by pain or other symptoms, he explains. The kidneys: how they work and the best ways to keep them healthy To make sure your kidneys are functioning properly, it’s important to be examined regularly by your general practitioner. A urine test strip can show, for example, whether they’ve excreted an unusually high amount of protein. “We’ve lately been heavily promoting urine albumin determinations,” says Dr Kai Martin Schmidt-Ott, a specialist in internal medicine and nephrology at Charité University Hospital in Berlin, Germany. Albumin is a protein found in the blood; one of its functions is to keep fluid from leaking out of the bloodstream. The kidneys filter the blood and remove waste products that are then excreted via urine. As healthy kidneys don’t remove proteins and other important nutrients, albumin excretions are associated with progressive disruption of kidney function and can indicate chronic kidney disease. Your GP can also have a laboratory test done on a blood sample to measure the level of creatinine, a waste product from the natural breakdown of muscle tissue. An elevated level of creatinine in the blood can be an early sign of diminishing kidney function. There are a number of things you can do to prevent kidney problems, the most important of which is maintaining a healthy diet, according to Schmidt-Ott. Avoid excess body weight, because the biggest risk factor for kidney disease is diabetes. People with a normal body weight have a lower risk of diabetes, and therefore of kidney problems too. For people who have healthy kidneys and want to keep them that way, Schmidt-Ott recommends “a Mediterranean, low-meat diet, trying to keep a healthy body weight, and foods low in salt.” A diet low in potassium – in consultation with a nephrologist, or kidney specialist – can be helpful for people with advanced kidney disease, he says. High blood pressure is another risk factor for kidney disorders and affects more than a billion people worldwide, according to the World Health Organization. Since high salt consumption can raise blood pressure, a low-salt diet is advisable. “We tell all patients we see as having a kidney problem that it’s imperative they stop smoking,” says Schmidt-Ott, explaining that nicotine is known to play a major role in cardiovascular diseases, which are closely linked to kidney disorders. Couple who quit drinking alcohol feel so much better – you can too Heavy alcohol consumption can damage the kidneys as well. Genetic factors and autoimmune diseases can also increase the risk of kidney disorders, as can taking pain relievers such as ibuprofen or diclofenac in large quantities. While popular wisdom holds that drinking a lot of fluids is good for your kidneys, this isn’t necessarily true, according to Lechterbeck, who says there’s no scientific proof that large fluid intake prevents the progression of kidney disorders. In fact, some patients with an advanced stage of kidney disease are told to drink less, he says, for example if water has accumulated in their body due to heart failure. Like what you read? Follow SCMP Lifestyle on Facebook, Twitter and Instagram. You can also sign up for our eNewsletter here.

Explainer | How your kidneys work and the best ways to take care of them

The kidneys regulate blood pressure, produce vitamin D and several hormones, stimulate red blood cell production, and much more Kidney disease has little pain and few symptoms; a healthy diet, with foods low in salt, is one of the best ways to keep them healthy

The kidneys regulate blood pressure, produce vitamin D and several hormones, stimulate red blood cell production, and much more

Kidney disease has little pain and few symptoms; a healthy diet, with foods low in salt, is one of the best ways to keep them healthy