Kidney Disease Quiz: Test Your Medical IQ

The kidneys are a pair of bean-shaped organs, located just below the ribcage on either side of the spine. They help filter your blood by removing waste and excess fluids, but they do much more. The kidneys help maintain the balance of electrolytes in the body. In addition, hormones produced by the kidney help regulate your blood pressure, make red blood cells, and help keep your bones strong.

Each day, the kidneys filter up to 150 quarts of blood and produce 1 to 2 quarts of urine, which is composed of body wastes and extra water. The urine passes from the kidneys through tubes called ureters, into the bladder where it is stored until it is filled. When the bladder reaches capacity, signals are sent to the brain that it is time to urinate, and the urine is released out of the body through a tube called the urethra.

"Renal" is the medical term that refers to kidney function. "Renal function" refers to the state of the kidneys, and how well they filter blood. Two healthy kidneys provide 100% of your renal function.

Kidney disease can have many different signs and symptoms that are non-specific, meaning, these same symptoms could also be signs of dysfunction in another body organ.

Some non-specific symptoms of renal disease include:
- Fatigue
- Weakness
- Difficulty concentrating
- Trouble sleeping
- Dry, itchy skin
- Frequent urge to urinate
- Blood in the urine
- Urine is foamy
- Puffiness around the eyes
- Loss of appetite
- Swelling in the ankles and feet
- Muscle cramps

It is possible to have kidney disease and have no symptoms for a long time. The damage to the kidneys can occur slowly and gradually, over many years, even decades. The most common causes of kidney damage include high blood pressure that is poorly managed, and uncontrolled diabetes.

A type of kidney disease that is genetic, or inherited, is polycystic kidney disease (PKD). Polycystic means "many cysts," and this disorder is characterized by cysts in both kidneys (bilateral renal cysts). These cysts can grow and cause the kidneys to get larger, while replacing the normal tissue. This can ultimately result in chronic kidney disease and kidney failure over time.

Hemodialysis is a process that removes waste products and extra fluids from the blood – a job usually performed by healthy kidneys – and it's one of the options for treating renal failure. Peritoneal dialysis is another treatment option that filters the wastes and fluids, but it does so by using the lining of your belly (the peritoneum). Dialysis is usually tried first when renal failure occurs. These options do not cure renal failure, but they can improve the quality of life, and extend the lifespan for someone in renal failure. The last resort option is a kidney transplant, whereby the patient receives a kidney from a living or recently deceased donor. This can be a cure, however, the organ may be rejected, and the patient will need to be on immunosuppressant medications for the rest of their life.

A nephrologist is a physician who specializes in kidney diseases.

There are 5 stages of chronic kidney disease:
- Stage 1: Normal kidney function, but there are signs that point to kidney disease
- Stage 2: Mildly decreased kidney function, and there are signs that point to kidney disease
- Stage 3: Moderately reduced kidney function
- Stage 4: Severely reduced kidney function
- Stage 5: Very severe reduction in kidney function; end stage renal failure

People on dialysis should maintain diets high in protein. High-quality protein produces less waste for removal during dialysis. Good sources for protein include meat, poultry, fish, and eggs.

It is important that people on dialysis reduce their intake of the mineral potassium. Potassium levels in the blood may build up and become elevated in between dialysis treatments and can affect your heartbeat. Too much potassium in the blood (hyperkalemia) can cause nausea, weakness, fatigue, irregular heartbeat, and can even lead to cardiac arrest and death.

Patients on dialysis need to follow a restricted diet, which may cause them to be deficient in certain nutrients. However, it is not a good idea to try to replenish those nutrients with over-the-counter vitamin and mineral supplements. Many supplements contain vitamins and minerals that can be harmful to patients on dialysis. A doctor can prescribe supplements that are appropriate.

Healthy kidneys work to remove excess fluid from your body and they do so regularly. A person on dialysis can have fluid buildup between treatments. Excess fluid can cause swelling and weight gain, elevated blood pressure, and a buildup of fluid in the lungs that makes it more difficult to breathe. Excess fluid also means the heart has to work harder. Patients on dialysis must carefully control fluid intake, and that includes fluid from foods such as fruits and vegetables. Salt should also be reduced or avoided, as it can make you thirsty, causing a greater fluid intake.

An excess of phosphorus in the blood can make skin feel itchy, and it can also pull calcium from the bones, leading to fractures. Processed foods are often high in phosphorus and should be avoided. Patients on dialysis should work with a dietician to manage dietary intake of phosphorus. Medications called phosphate binders may be prescribed to help absorb phosphorus from the food and allow it to pass through the body without being absorbed into the bloodstream.

The most common cause of renal failure in the U.S. is diabetes. The U.S. Renal Data System ranks the top causes of kidney failure as follows:
1. Diabetes (43.8% of new cases of kidney failure)
2. High blood pressure (26.8%)
3. Glomerulonephritis (7.6%)
4. Cystic diseases (2.3%)
5. Urologic diseases (2.0%)
6. Other causes, combined (17.5%)