Kidney Disease
Kidney disease, also called renal disease, refers to a variety of conditions affecting the kidneys. According to the National Kidney Foundation, 1 in 3 Americans are at risk of developing kidney disease.
What Is Kidney Disease?
The kidneys are a pair of bean-shaped organs in the abdomen that filter excess water and waste material from the blood. Your body eliminates that excess waste as urine. Kidney disease occurs when damaged kidneys are unable to filter blood as well as they should. Water and waste products accumulate in the body, causing a range of symptoms. Left untreated, kidney disease can progress to kidney failure.
Types of Kidney Disease
Common types of kidney disease include:
- acute kidney injury, such as sudden kidney damage or failure
- chronic kidney disease, which is long-term kidney dysfunction that can progress to kidney failure
- kidney cysts
- kidney stones
- polycystic kidney disease, a genetic disorder that causes numerous cysts
- pyelonephritis, a severe urinary tract infection
- viral infections, such as hepatitis B and hepatitis C
Stages of Kidney Disease
Chronic kidney disease is different from acute kidney disease in that it can progress through several stages. These stages are defined by the impact on kidney function.
- Stage 1: normal function
- Stage 2: mild reduction in functioning
- Stage 3: moderate reduction in functioning
- Stage 4: severe reduction in functioning
- Stage 5: kidney failure, also called end-stage renal disease
Causes of Kidney Disease
The most common causes of end-stage kidney damage and disease are diabetes and high blood pressure. Other causes include:
- autoimmune diseases, such as systemic lupus erythematosus
- birth defects in the urinary tract
- certain cancers
- genetic conditions
- inflammation of the glomerulus caused by infection or a drug
- inflammation of the tubules caused by a drug allergy
- obstructions of the urinary tract, such as enlarged prostate
- vesicoureteral reflux, a condition in which urine flows backward into one or both ureters and sometimes the kidneys
Signs and Symptoms of Kidney Disease
Kidney disease may not cause any symptoms in the early stages. If symptoms do occur, they may include:
- anemia (low red blood cells)
- fatigue and weakness
- high blood pressure
- muscle spasms
- nerve damage
- nutritional deficiencies, such as low vitamin D
- increased or reduced urine output
- shortness of breath
- swollen feet and ankles
- trouble thinking
How Kidney Disease Is Diagnosed
Kidney disease is diagnosed using laboratory tests of kidney function including:
- albumin — a test that detects protein in the urine
- creatinine — a test for waste product in the blood
- glomerular filtration rate — a test that measures kidney function
If evidence of kidney disease is found, additional tests may include:
- imaging tests, such as an ultrasound, to check kidney condition
- kidney biopsy to look for the cause of kidney disease and extent of damage
Treatments for Kidney Disease
Chronic kidney disease has no known cure. Treatments for kidney disease aim to manage symptoms, preserve kidney function and slow disease progression. Options may include:
- medications to control blood pressure and blood sugar, as well as address symptoms
- physical activity to control weight, blood pressure and blood sugar
- special eating plans lower in sodium, protein, potassium and phosphorous (all nutrients that can further damage kidneys)
With prompt diagnosis and treatment, it may be possible to slow down kidney disease before it progresses to the end-stage. When end-stage renal disease develops, kidney function ceases permanently and patients require kidney dialysis or transplant to survive.