Kidney Disease and Kidney Function Tests: A Narrative Review

The kidney is a vital organ responsible for maintaining overall body homeostasis through its role in renal function. This function includes filtration, reabsorption, secretion, and excretion processes essential to the regulation of fluids, electrolytes, and waste products. The kidney's primary role is to filter blood through the glomerulus, removing toxins and metabolic byproducts while retaining necessary proteins and cells. This filtration process forms urine, which collects waste and excess substances, eventually excreted from the body. Additionally, the kidney balances electrolytes, including sodium, potassium, and calcium, and regulates blood pH through acid-base equilibrium. By releasing hormones like erythropoietin, which stimulates red blood cell production, and renin, which modulates blood pressure, the kidney plays a critical role in endocrine function. It also contributes to bone health through vitamin D activation, essential for calcium absorption. Impaired kidney function, from acute or chronic conditions, can disrupt these homeostatic processes, leading to systemic health issues, including hypertension, anemia, and mineral imbalances. Understanding renal function mechanisms is crucial in preventing and managing kidney diseases, enhancing patient outcomes, and improving quality of life.