Kidney disease occurs when the kidneys are not functioning properly, which usually results from an attack on the nephrons, causing them to lose their filtering ability.
Classifications of Kidney Disease
- Acute Renal Failure (ARF) happens quickly and may be a result of (1) an accident that injures the kidneys; (2) losing a lot of blood; or (3) drugs or poisons. ARF may lead to permanent loss of kidney function, but if the kidneys are not seriously damaged, ARF may be reversed.
- Chronic Kidney Disease (CKD) occurs over time when the kidneys do not remove toxins, waste products, and fluids from the body properly. CKD can be managed to slow the progression of the disease.
- End Stage Renal Disease (ESRD) is an irreversible decline in kidney function, which is severe enough to be fatal without dialysis or transplantation.
Causes of Chronic Kidney Disease (CKD)
The two most common causes of CKD are diabetes and high blood pressure.
- Diabetes is a disease that prevents the body from using glucose (sugar) as it should. If glucose stays in the blood instead of breaking down, it can act like a poison. Damage to the nephrons from unused glucose is called diabetic nephropathy. This condition can be delayed and prevented by keeping glucose levels down.
- High blood pressure can damage the small blood vessels in the kidneys. Blood pressure medications called angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) have been found to protect the kidneys more than other medicines that lower blood pressure levels.
Other causes of kidney disease include:
- Autoimmune, infection-related and sclerotic diseases attack the tiny blood vessels within the kidney. Protein, blood or both in the urine are often the first signs of these diseases. Treatments may include immunosuppressive drugs or steroids to reduce inflammation and proteinuria.
- Inherited or congenital kidney diseases result from hereditary factors. Polycystic kidney disease (PKD) is a genetic disorder in which many cysts grow in the kidneys. PKD cysts can slowly replace much of the mass of the kidneys, reducing kidney function and leading to kidney failure.
Symptoms of Kidney Disease
Kidney disease is often referred to as “the silent disease” because in early stages, symptoms often go unnoticed because most people do not feel sick. Symptoms include:
- Difficulty concentrating
- Fluid buildup, such as swelling in the legs, hands or face
- Itchy skin
- Loss of sleep
- Shortness of breath
- Upset stomach, poor appetite, vomiting
- Weakness, fatigue, and lack of energy
How Is Kidney Function Tested?
- Proteinuria screen – A urine test can detect protein in the urine, which is called proteinuria. Normally, there is no protein in the urine. Finding protein in the urine usually means that the kidneys’ filters are leaky – a sign of kidney damage.
- Serum creatinine – A blood test that measures the amount of creatinine (kre-AT-i-nin) in the blood. Creatinine is a waste product resulting from the natural breakdown of muscle tissue. A high creatinine level may mean that the kidneys are not working properly.
- Creatinine clearance – A urine and blood test that shows how well the kidneys are filtering creatinine from the blood. Normal creatinine clearance means that the kidneys are working well. Creatinine clearance decreases when the kidneys are not functioning properly.
- Blood urea nitrogen (BUN) – A blood test that measures the amount of urea nitrogen (a waste product) in the blood. A high BUN level may mean that the kidneys are not working properly.
- Renal imaging– An ultrasound, CT scan, and MRI are imaging tests that let your doctor see your kidneys and may show possible reasons for decreased kidney function (for example, an unusual growth or blockage).
- Renal biopsy – A procedure in which the doctor uses a needle to take a tiny piece of your kidney to examine under a microscope. A local anesthetic is used to numb the area on the back where the needle is inserted.
Glomerular Filtration Rate (GFR) Stages of Kidney Disease & Treatment
GFR is considered the best indicator of how well the kidneys are working. It is a calculation based on serum creatinine, age, gender, and race that determines the stage of kidney disease and necessary clinical action. In 2002, the National Kidney Foundation published treatment guidelines that identified five states of CKD based on declining GFR measurements.
Stage | Description | Treatment |
1 | Kidney damage present with no decrease in kidney function | Slow the progression of CKD and reduce the risk of heart and blood vessel disease |
2 | Kidney damage present with slight decrease in kidney function | Estimate and treat the progression of CKD |
3 | Kidney damage present with a moderate decrease in kidney function | Treat complications, including anemia and bone health, and monitor progression |
4 | Kidney damage present with a severe decrease in kidney function | Treat complications and prepare for transplantation or dialysis |
5 | Kidney failure | Transplantation, dialysis or no treatment |
How to Manage and Slow Kidney Disease Progression
Early detection of kidney disease allows for early intervention and treatment. Kidney disease tends to get worse over time, but there are several ways to slow the progression.
- Bring diabetes under control. Studies show that people with diabetes who keep their blood sugar levels close to normal are at lower risk for developing kidney failure.
- Control blood pressure. Work to reduce blood pressure to 130/85 through diet and/or medication.
- Treat anemia (low number of red blood cells). Kidney disease often leads to anemia which can cause fatigue, weakness, and may contribute to heart problems.
- Diet, nutrition and exercise. Dietary needs change with the progression of kidney disease. Maintain a balanced diet based on current nutritional needs. Develop a diet and exercise regimen under the guidance of a physician.
- Stay away from medications that can harm the kidneys. Some medicines can damage the kidneys. Pain relievers such as aspirin, ibuprofen and naproxen may make kidney disease worse. Consult a physician regarding medications or food supplements.
To watch a video explaining kidney disease, click here.
