The kidneys are a pair of vital organs that perform many functions to keep the blood clean and chemically balanced. Understanding how the kidneys work can help a person keep them healthy. They are bean shaped and when held in the hand they are about the size of a fist. Just like any other organ that functions continually without break, the kidneys can develop problems. And these problems are addressed as kidney diseases.
Understanding the Functions of Kidneys
The kidneys are bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage, one on each side of the spine. The kidneys are sophisticated reprocessing machines. Every day, a person’s kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water. The wastes and extra water become urine, which flows to the bladder through tubes called ureters. The bladder stores urine until releasing it through urination.
The kidneys remove wastes and water from the blood to form urine. Urine flows from the kidneys to the bladder through the ureters.
Wastes in the blood come from the normal breakdown of active tissues, such as muscles, and from food. The body uses food for energy and self-repairs. After the body has taken what it needs from food, wastes are sent to the blood. If the kidneys did not remove them, these wastes would build up in the blood and damage the body.
The actual removal of wastes occurs in tiny units inside the kidneys called nephrons. Each kidney has about a million nephrons. In the nephron, a glomerulus—which is a tiny blood vessel, or capillary—intertwines with a tiny urine-collecting tube called a tubule. The glomerulus acts as a filtering unit, or sieve, and keeps normal proteins and cells in the bloodstream, allowing extra fluid and wastes to pass through. A complicated chemical exchange takes place, as waste materials and water leave the blood and enter the urinary system.
At first, the tubules receive a combination of waste materials and chemicals the body can still use. The kidneys measure out chemicals like sodium, phosphorus, and potassium and release them back to the blood to return to the body. In this way, the kidneys regulate the body’s level of these substances. The right balance is necessary for life.
In addition to removing wastes, the kidneys release three important hormones:
- erythropoietin, or EPO, which stimulates the bone marrow to make red blood cells
- renin, which regulates blood pressure
- calcitriol, the active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body.
How Kidney Diseases Develop
To be specific, the meaning of a kidney disease is that the kidneys have failed to work effectively i.e. they can no longer remove wastes and extra water from the body as they are ideally supposed to. Kidney diseases are most notably caused by high blood pressure or diabetes. Some of the risk factors for kidney diseases include:
- high blood pressure
- family history of kidney diseases or kidney failure
- cardiovascular diseases.
Each kidney consists of about a million small filtering units that are made up of blood vessels. When a person is suffering from diabetes or high blood pressure, these blood vessels get damaged and the kidneys fail to filter blood as effectively as they are supposed to. As more and more filtering units begin to get damanged by these diseases, the kidneys begin to fail to work even more.
Kidney diseases that are in their early stage tend to have no symptoms, implying that the person will not feel a thing even if he/she is suffering from the disease. It is therefore, necessary to go for regular medical check-ups to spot any irregularities.
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