The Kidneys and Their Function

Most people are born with two kidneys, although one kidney alone is sufficient to perform the body’s essential functions.

• The kidneys lie at the back of the abdominal cavity, surrounded by fatty tissue and protected by the spine and lower ribs.

• The right kidney sits slightly lower than the left.

• Each kidney weighs about 150 grams.

• From each kidney, a ureter carries urine to the bladder, and from the bladder, urine exits the body through the urethra.

Functions of the Kidneys

Function of the kidneys
The kidneys perform multiple vital functions essential for life. They filter waste products—especially nitrogenous waste—from the blood, maintain salt and fluid balance through filtration and secretion, help regulate the body’s acid–base balance, influence blood pressure control, and stimulate red blood cell production by releasing the hormone erythropoietin.

Chronic Kidney Disease and Kidney Failure

Kidney failure is a condition in which the kidneys can no longer perform their function, and the body fails to eliminate excess fluid and waste products. It may result from acute or chronic kidney disease.

Chronic kidney disease (CKD) is divided into five stages based on kidney function.
Stage 5 is considered end-stage kidney failure, when the glomerular filtration rate (GFR) falls below 15 ml/min/1.73 m².

Treatment and Stages of the Disease

When a person is diagnosed with kidney disease, treatment and symptom management are often possible with medication.
The goal of treatment for chronic kidney disease is mainly to slow or prevent further decline in kidney function, thereby delaying or avoiding progression to end-stage kidney failure.

End-stage kidney failure is a life-threatening condition where the kidneys lose all function, stop producing urine, and the kidney tissue becomes permanently damaged.
The incidence of end-stage kidney failure has been steadily increasing worldwide in recent decades.

A person with end-stage kidney failure requires dialysis or a kidney transplant. Symptoms can sometimes be managed for a time with specialised medication and nutritional therapy.

The Most Common Causes of End-Stage Kidney Failure

• Glomerulonephritis

• Chronic interstitial nephritis

• Hereditary polycystic kidney disease

• Hypertension (high blood pressure)

• Diabetes mellitus

• Renal vascular disease

Infections and certain medications can also cause kidney damage and, in some cases, kidney failure.