What is a nephrologist?

A nephrologist is an internist who then pursued further training in nephrology, which is the study and care of kidney disease. They take care of kidney disease, hypertension and other disorders of the kidney such as kidney stones. They are the only physicians trained to provide dialysis for kidney failure. They are also part of the kidney transplant team.

What is the difference between a nephrologist and urologist?

A nephrologist is an internist for your kidneys. They use medications to treat kidney disease. A urologist is a surgeon who has specialized in surgical disorders of the kidney, bladder and prostate.

What are the kidneys and how do they function?

There are two kidneys, each about the size of a fist, located on either side of the spine at the lowest level of the rib cage. Each kidney contains up to a million functioning units called nephrons. A nephron consists of a filtering unit of tiny blood vessels called a glomerulus attached to a tubule. When blood enters the glomerulus, it is filtered and the remaining fluid then passes along the tubule. In the tubule, chemicals and water are either added to or removed from this filtered fluid according to the body’s needs, the final product being the urine we excrete.

The kidneys perform their life-sustaining job of filtering and returning to the bloodstream about 200 quarts of fluid every 24 hours. About 2 quarts are removed from the body in the form of urine, and about 198 quarts are returned to the body. The urine we excrete has been stored in the bladder for anywhere from 1 to 8 hours.

What is creatinine?

Creatinine is a waste product made by your muscles. It is freely filtered by the kidneys and is used as a marker for kidney function. When the creatinine increases in the blood it means the kidney function is decreasing.

What is chronic kidney disease (CKD)?

Chronic kidney disease includes conditions that damage your kidneys and decrease their ability to keep you healthy. If kidney disease gets severe, wastes can build to high levels in your blood and make you feel sick. You may develop complications like high blood pressure, anemia (low blood count), weak bones, poor nutritional health and nerve damage. Also, kidney disease increases your risk of having heart and blood vessel disease. These problems may happen slowly over a long period of time or quickly over a few months. Chronic kidney disease may be caused by diabetes, high blood pressure and other disorders. Early detection and treatment can often keep chronic kidney disease from getting worse. When kidney disease progresses it may eventually lead to kidney failure, which requires dialysis or a kidney transplant to maintain life.

Approximately 11% of US adults have CKD. The condition is usually asymptomatic until its advanced stages. Most cases of CKD are associated with diabetes or hypertension (high blood pressure).

View the CKD Stages

What causes chronic kidney disease (CKD)?

The two main causes of CKD are diabetes and high blood pressure, which are responsible for up to two-thirds of cases in the U.S.

Other conditions that affect the kidneys are:

  • Glomerulonephritis – a group of diseases that cause inflammation and damage to the kidney’s filtering units. These disorders are the third most common type of kidney disease.
  • Inherited disease – such as polycystic kidney disease, which causes large cysts to form in the kidneys and damage the surrounding tissue.
  • Malformations that occur as a baby develops in its mother’s womb.
  • Lupus and other diseases that affect the body’s immune system.
  • Obstructions caused by kidney stones, tumors or an enlarged prostate gland in men.
  • Repeated urinary tract infections.

What are the symptoms of chronic kidney disease?

Most people may not have any symptoms until their kidney disease is advanced. However, you may notice that you:


  • Feel more tired and have less energy
  • Have trouble concentrating
  • Have a poor appetite
  • Have trouble sleeping
  • Have muscle cramping at night
  • Have swollen feet and ankles
  • Have puffiness around your eyes, especially in the morning
  • Have dry, itchy skin
  • Need to urinate more often, especially at night

How is chronic kidney disease detected?

Early detection and treatment of CKD are the keys to keeping kidney disease from progressing to kidney failure. The most common test is a blood test for creatinine, which is used to calculate your glomerular filtration rate (GFR). Your GFR tells you how much kidney function you have. Another test looks for protein in the urine. An excess amount of protein in your urine may mean your kidney’s filtering units have been damaged by disease.

What are my treatment options with chronic kidney disease?

Learn your treatment options if you have stage 4 or 5 kidney disease:

Fresenius Kidney Care


I was told that I need a kidney biopsy. What is that?

A kidney biopsy involves taking a tiny piece of your kidney to use for special tests. The test results will help your doctor decide what treatment you need to help your kidneys work properly. It will also tell your doctor how much chronic damage or scarring is present in your kidney, this can help determine your long-term kidney prognosis.

An interventional radiologist will be the doctor who will perform the biopsy. You will be under light sedation and a local painkiller is injected into the skin to minimize pain where the biopsy needle will enter. Generally only mild discomfort is felt. The biopsy usually only takes 30 to 60 minutes and then you must lay on your back for two to three hours after to ensure there is no bleeding.

It is important to discuss with you doctor the risks associated with kidney biopsy.

What is the parathyroid hormone and why does my doctor check this?

The parathyroid hormone (PTH) is a hormone that comes from your parathyroid glands. These are 4 small glands located around your thyroid gland. In kidney disease this hormone becomes elevated and can cause a number of problems in your body. This condition is called Secondary Renal Hyperparathyroidism.

What is the GFR?

The GFR or Glomerular Filtration Rate is a way of measuring kidney function through a calculation of serum creatinine, age and gender. This is measured during a 24 hour urine collection. More information can be found about the GFR through the National Institutes of Health.

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