High blood sugar can be an early symptom of kidney disease: Causes, warning signs, and prevention tips | – The Times of India

High blood sugar, or hyperglycaemia, is a key warning sign that your kidneys may be under strain. Although it is often associated with diabetes, consistently high glucose levels can independently cause kidney damage and increase the risk of chronic kidney disease (CKD). The kidneys play a vital role in filtering waste, maintaining fluid balance, and regulating blood pressure. However, when blood sugar remains elevated for long periods, it can damage the tiny blood vessels and filters within the kidneys, impairing their ability to function properly. Over time, this can lead to serious complications such as reduced kidney efficiency, fluid retention, and even kidney failure if left unmanaged.

According toa study published in The Bidirectional Link Between Diabetes and Kidney Disease: Mechanisms and Management, persistently high blood sugar causes damage to the tiny blood vessels and filtering units in the kidneys, leading to reduced function and increased risk of chronic kidney disease.

1. The filter system is under strainEach kidney contains millions of tiny filtering units called nephrons, which work continuously to cleanse the blood. When blood sugar remains high, it damages the small blood vessels and filtering structures inside the kidneys. This can:Narrow and clog the blood vessels, reducing blood flow to the kidneysCause protein leakage into the urine (albuminuria), an early marker of kidney damageIncrease internal pressure in the filters (hyperfiltration), worsening injury over time2. The role of blood pressure and toxinsHigh blood sugar often goes hand in hand with high blood pressure, and together, they accelerate kidney damage. Excess glucose also leads to the build-up of metabolic waste and toxins, triggering inflammation and scarring in kidney tissues.3. The vicious cycleAs kidney function declines, the body becomes less efficient at removing glucose and waste products. This, in turn, makes it harder to control blood sugar levels, creating a cycle of worsening kidney health. Experts have noted that high blood sugar and kidney dysfunction can feed into one another, aggravating both conditions.

1. Protein in urine (Microalbuminuria)One of the earliest and most reliable indicators of kidney damage is the presence of protein in the urine. This means the kidneys’ filters have become leaky, allowing essential proteins to pass through.2. Increased urination or nocturiaHigh glucose levels cause the kidneys to work harder to remove excess sugar, leading to frequent urination, especially at night. Over time, this can strain the kidneys and lead to dehydration.3. Swelling or puffiness (Oedema)When kidneys struggle to filter fluid effectively, it can accumulate in the body, leading to noticeable swelling in the feet, ankles, or around the eyes.4. Persistent high blood pressureHigh blood sugar can worsen hypertension, and elevated blood pressure is a key indicator of kidney strain. This two-way relationship often accelerates the decline in kidney function.5. Declining kidney functionAs damage progresses, the kidneys become less capable of filtering waste. This may not cause immediate symptoms but is often detected through blood and urine tests showing reduced filtration rate (eGFR) and higher waste levels.

The most common cause of high blood sugar–related kidney disease. Uncontrolled diabetes dramatically increases the risk of chronic kidney damage.Duration and severity of hyperglycaemiaThe longer your blood sugar stays high, the greater the risk of developing kidney disease. Consistent glucose management helps delay or prevent damage.High blood pressureElevated blood pressure combined with high blood sugar puts added stress on the delicate kidney filters, worsening long-term damage.Lifestyle factorsBeing overweight, smoking, following a poor diet, and leading a sedentary lifestyle all contribute to insulin resistance and kidney stress.

A family history of kidney disease or diabetes increases your vulnerability. Certain ethnic groups are also at higher risk of developing diabetic kidney complications.

Even if you feel well, schedule regular kidney health check-ups, especially if you have diabetes or prediabetes. Early changes often occur without obvious symptoms.Disclaimer: This article is for informational purposes only and should not be considered medical advice. Please consult a healthcare professional before making any changes to your diet, medication, or lifestyle.Also read | Renal failure or kidney failure: Are they the same? Know the meaning, symptoms, and causes