What do the kidneys do?
The kidneys are two organs located on either side of the spine, just below the rib cage. Their main job is to filter the blood and remove waste and extra fluid from the body through urine. They also help control blood pressure and maintain the right balance of minerals and fluids in the blood.
Inside each kidney are millions of tiny filtering units called nephrons. Each nephron contains small blood vessels that filter the blood while allowing useful substances to remain in the body. Because these filters depend on tiny blood vessels working properly, they can be vulnerable to damage caused by diabetes.
How can diabetes damage the kidneys?
When blood glucose stays too high for a long period of time, it can damage the blood vessels in the kidneys and the nephrons that filter the blood. Over time, the kidneys may become less effective at filtering waste.
One of the earliest signs of kidney damage can be albuminuria, which means that a protein called albumin begins appearing in the urine. Healthy kidneys normally keep most albumin in the blood. When the kidney’s filters become damaged, more albumin can pass into the urine.
The problem is that kidney disease can develop slowly and often does not cause noticeable symptoms in its early stages. A person may have kidney damage without realizing anything is wrong.
Why is blood pressure important?
Blood glucose is not the only factor that can affect kidney health. High blood pressure can also put additional stress on the kidneys and contribute to kidney damage.
Diabetes and high blood pressure can also create a cycle in which both conditions place extra strain on the kidneys. This is one reason healthcare providers monitor blood pressure as well as blood glucose in people with diabetes.
Finding kidney damage early
Because diabetic kidney disease may not cause noticeable symptoms at first, testing is an important part of catching it early.
Healthcare providers can use blood and urine tests to check how well the kidneys are working. A urine test can measure albumin, while a blood test can be used to estimate the kidneys’ filtering ability through a measurement called estimated glomerular filtration rate, or eGFR.
The American Diabetes Association recommends regular testing for kidney disease in people with diabetes. For example, it recommends assessing kidney function at least annually in people with type 2 diabetes and in people with type 1 diabetes who have had the condition for at least five years.
Protecting the kidneys
Managing diabetes is also an important part of protecting kidney health. Keeping blood glucose and blood pressure within the ranges recommended by a healthcare provider can help reduce the risk of kidney damage or slow its progression.
Healthcare providers may also recommend medications that can help protect kidney function for people who have diabetes and kidney disease. Some medications used to treat type 2 diabetes can also provide kidney benefits for certain patients with chronic kidney disease.
Regular checkups matter too. Because kidney damage can develop without obvious symptoms, testing can reveal changes that a person would not necessarily notice on their own.
When kidney damage becomes more serious
If chronic kidney disease continues to progress, the kidneys can gradually lose their ability to filter waste and extra fluid from the blood.
In advanced cases, a person may develop kidney failure and require dialysis or a kidney transplant. Diabetes is a major cause of kidney failure in the United States, which makes prevention and early detection especially important.
Why kidney health matters
The kidneys constantly filter the blood, and damage to their tiny blood vessels can gradually interfere with this essential process.
The good news is that kidney disease does not have to be an inevitable outcome of diabetes. Regular testing, managing blood glucose and blood pressure, and working with healthcare providers can help identify kidney problems early and reduce the risk of serious complications.
Understanding how diabetes affects the kidneys is another reminder that diabetes management is about protecting the organs that keep the body functioning properly.