How kidneys fail
Kidneys maintain the chemistry of the body. They clean the body’s entire blood supply every 5 minutes. Approximately 200 quarts of blood flow through your kidneys every 24 hours. The kidneys have two main functions: excretory and endocrine. Excretory functions include filtering out all the waste products and excess water in the form of urine and balancing mineral and acidity levels in your body. Endocrine functions include making an enzyme which helps control your blood pressure, producing a hormone that stimulates bone marrow to make red blood cells, and activating vitamin D to keep your bones healthy and strong.
Kidneys fail due to:
- High blood pressure (hypertension)
- Glomerular diseases
- Polycystic kidney disease
- Birth defects
- Autoimmune diseases
The most common cause of kidney damage is diabetic nephropathy, which is caused by diabetes. Diabetes prevents the body from processing sugar, also called glucose, properly. High blood sugar level becomes dangerous because they damage blood vessels, including the tiny vessels in the kidneys, which are responsible for filtering waste and excess fluid.
Damaged kidneys cannot remove excess water or waste efficiently from the blood. Waste and fluid then build up in the body, causing more damage to the kidneys. Eventually, the kidneys will fail. Kidney failure due to diabetes happens slowly. A person may not recognize symptoms until their kidneys cannot function anymore, and dialysis or kidney transplantation is required. Regular doctor visits can help detect kidney problems early so progression of kidney failure can be managed to help kidneys work as long as possible.
High blood pressure
High blood pressure and kidney disease are related. High blood pressure can cause kidney damage, and kidney damage can cause high blood pressure. High blood pressure is the second leading cause of kidney disease.
High blood pressure damages the tiny blood vessels in the kidneys, which prevents them from cleaning the blood of excess fluid and wastes.
The only way to detect high blood pressure is to have your blood pressure taken regularly, because most patients may not experience any symptoms. Steps to help manage high blood pressure include:
- Controlling your weight
- Limiting sodium intake
- Getting plenty of exercise
- Limiting or avoiding alcohol consumption
- Not smoking
- Taking your prescription medication as advised by your doctor
Each kidney contains a million clusters of looping blood vessels that act as tiny filters. Each cluster is called a glomerulus. (More than one are called glomeruli.) Each glomerulus attaches to the opening of a small fluid-collecting tube called a tubule. As blood passes through the glomeruli, fluid and wastes are filtered out. The cleaned blood returns to the bloodstream, while the filtrate flows through the tubules. Tubules are surrounded by blood vessels that reabsorb what the body needs. The remaining fluid waste becomes urine. Glomerular diseases damage the kidneys’ ability to remove waste and excess fluids. Glomerular diseases fall into two categories:
- Glomerulonephritis – Inflammation of the glomeruli
- Glomerulosclerosis – Scarring or hardening of the glomeruli
Glomerular diseases can occur acutely (suddenly) or chronically (over time). There are several known causes of glomerular disease, including: diabetes, lupus, other autoimmune diseases, toxic drugs and infections. In many cases, however, the cause is unknown.
Polycystic kidney disease (PKD)
Polycystic kidney disease (PKD) is a disorder in which non-cancerous (benign) cysts develop. The cysts are filled with a water-like fluid and can occur throughout the body, but affect the kidneys most severely. They vary in size, but as they accumulate they can grow extremely large.
Polycystic kidney disease is genetic, which means the disease runs in families. One of the greatest risks for people with PKD is developing high blood pressure, which can accelerate kidney disease.
Other causes of kidney failure
Birth defects can cause kidneys to fail. Some babies are born without kidneys or with abnormal kidneys. Another problem can be caused by a blocked urine flow. If a blockage develops between the kidneys and urethra, the opening where the urine leaves the bladder, the urine can back up and cause kidney damage.
Autoimmune diseases can affect the body’s immune system and hurt the organs, including the kidneys. Patients who have lupus (a chronic inflammatory disease) can be at risk for kidney disease.
The obstruction of normal urine flow caused by kidney stones, tumors or an enlarged prostate gland can lead to infections that cause kidney failure.
Chronic urinary tract infections (UTI) may also cause permanent kidney damage. It’s important to consult a doctor if urinary tract infection symptoms occur repeatedly.
Being diagnosed with kidney disease can be upsetting, but there are ways of treating it. People with kidney disease should develop a plan of action with their doctor and dietitian. Medications can be prescribed to stabilize potassium and phosphorus levels, as well as help manage high blood pressure and blood glucose (sugar). For people with late stage chronic kidney disease (CKD), dialysis or kidney transplantation are treatment options.
Kidneys can fail because of conditions such as diabetes, high blood pressure and other medical issues. Understanding how kidneys fail and what to do to slow the progression of kidney disease will help you discuss treatment options with your doctor.
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