Understanding the role and functions of the kidneys

Humans have two kidneys located at the back under the ribs in the waist area. They are shaped like beans and measure about 10 – 13 centimeters in adults. Their function is to remove waste and excess water from the blood and excrete it as urine. The kidneys consist of many units called nephrons, with about 1 million nephrons per kidney. Nephrons deteriorate with age and cannot be regenerated to replace the lost ones. The kidneys have three main functions:

1. Eliminate various wastes through urine, including urea (BUN), creatinine, uric acid, drugs, and foreign substances. They can also reabsorb beneficial substances for the body, such as sugar and protein.
2. Maintain the balance of water and minerals in the blood within normal limits. These minerals include sodium, potassium, calcium, phosphate, and acids in the body.
3. Produce several hormones, such as
   1. Substances that stimulate the bone marrow to produce red blood cells, such as erythropoietin.
   2. Substances that strengthen bones, including vitamin D, which increases calcium absorption in the intestines and kidneys.
   3. Substances that regulate blood pressure, such as renin, which raises blood pressure levels.

What is kidney deterioration or kidney failure?

Kidney deterioration or kidney failure is a condition where kidney function decreases. Kidney failure can be divided into two types:

1. Acute kidney failure is a condition where kidney function rapidly decreases. Some cases may be severe enough to require temporary dialysis. With proper care and treatment, the kidneys can return to normal function.
2. Chronic kidney failure, currently called chronic kidney disease, is a condition where kidney function gradually decreases over a period longer than 3 months. Even with proper treatment, the kidneys cannot return to normal function. Chronic kidney disease is like a staircase with multiple stages, divided into 5 stages from stage 1 to 5. As kidney deterioration progresses to stage 5 or end-stage kidney failure, it requires kidney replacement therapy, including permanent hemodialysis, permanent peritoneal dialysis, or kidney transplantation. Patients at this stage may present with symptoms such as nausea, vomiting, fatigue, pallor due to erythropoietin hormone deficiency, increased swelling, decreased urine output, inability to lie flat, pulmonary edema, seizures, etc. How can one know if kidney deterioration has begun and at what stage? When should preparations for dialysis or kidney replacement begin? These questions are frequently asked. The answer starts with understanding the causes of kidney failure and how to diagnose it early to prevent rapid kidney deterioration.

Dialysis Center, Phyathai 2 Hospital, 14th Floor, Building A, Tel. 02-617-2444 ext. 1683, 1684