What is chronic kidney disease?

Chronic kidney disease (CKD) or chronic renal failure is the slow and gradual loss of kidney function. When not identified and treated, it can lead to kidney failure.

The kidneys are organs responsible for filtering substances and nutrients in the body. Essential components are absorbed, while toxic ones are eliminated through urine. This balance is crucial for controlling blood pressure and regulating calcium and phosphorus levels in the blood, contributing to bone health and the maintenance of red blood cells, whose deficiency can lead to anemia.

According to data from the Brazilian Society of Nephrology (SBN), the global prevalence of chronic kidney disease is 7.2% among individuals over 30 years old and between 28% and 46% among those over 64. In Brazil, it is estimated that more than ten million people have the disease. Of these, 90,000 are undergoing dialysis (a process that artificially stimulates kidney function, usually when the organs are functioning at only 10%), a number that has increased by more than 100% in the last ten years.

Causas

Chronic kidney disease is associated with two highly prevalent conditions in the Brazilian population: high blood pressure and diabetes.

Since the kidneys play a key role in regulating blood pressure, when they do not function properly, blood pressure levels can become imbalanced. Conversely,These changes in blood pressure can also overload the kidneys. Therefore, hypertension can be both a cause and a consequence of kidney dysfunction, and its control is essential for preventing the disease. According to the Brazilian Society of Nephrology (SBN), 35% of patients who required dialysis in 2011 had been diagnosed with hypertension.

Diabetes, on the other hand, can damage the blood vessels in the kidneys, impairing their ability to filter blood properly. More than 25% of people with type 1 diabetes and 5% to 10% of those with type 2 diabetes develop kidney failure.

Other causes include: nephritis (inflammation of the kidneys), hereditary cysts, frequent urinary tract infections that damage the urinary tract, and congenital diseases.

Symptoms

The slow progression of the disease allows the body to adapt to the decline in kidney function. As a result, in many cases, the disease does not show symptoms until the kidneys are severely compromised.

In such cases, the signs may include: increased volume and changes in the color of urine, discomfort while urinating, swelling in the eyes, ankles, and feet, lower back pain, anemia, weakness, nausea and vomiting, changes in blood pressure.

Diagnosis

Kidney dysfunction can be identified through two tests: a urine test and a blood test. The urine test detects the presence of a protein called albumin, while the blood test checks for another protein, creatinine. When kidney function is impaired, the kidneys eliminate or absorb substances in a disordered way, causing an imbalance in the body.

Prevention

The first step is to prevent the development of high blood pressure and to manage diabetes, the two main conditions that lead to kidney failure. Therefore, controlling blood pressure levels, maintaining a balanced diet with low salt and sugar intake, eliminating habits such as smoking, reducing alcohol consumption, engaging in physical activity, and having regular medical check-ups are essential actions.

Treatment

Kidney failure can be treated with medication and dietary control. In more severe cases, dialysis or kidney transplantation may be necessary (as a definitive therapy to replace kidney function).

Brazil has the largest public kidney transplant program in the world. In 2011, 4,957 kidney transplant surgeries were performed.

References

Brazilian Society of Nephrology
National Kidney Foundation

By Einstein Editorial Board