Frequently asked questions

The main function of the kidney is to filter blood to get rid of by-products of metabolism and to eliminate these wastes along with excess fluid from the bloodstream into the urine. The kidneys maintain the balance of electrolytes such as sodium, potassium, calcium, and phosphorus in the body, and they play a role in bone health by manufacturing vitamin D. The kidneys also maintain your body's blood counts by secreting the hormone erythropoietin (EPO) whose function is to stimulate red blood cell production by the bone marrow.

Common reasons include an elevated creatinine, a decreased eGFR, high blood pressure, protein in the urine, blood in the urine, or kidney stones. Creatinine is a product of muscle breakdown that the kidneys clear, so higher-than-normal levels may reflect reduced kidney function. eGFR estimates how well the kidneys filter the blood. High blood pressure can both signal and cause kidney problems. Protein or blood in the urine can indicate damage to the kidney's filters, and kidney stones can be evaluated to reduce the chance of forming more.

At times during an evaluation we will ask you to collect a 24-hour urine specimen to measure kidney function and the amount of various substances in the urine, such as protein, calcium, and uric acid. Collect it on a day you are home all day. When you wake up, urinate into the toilet and flush it, noting the time as the start. From then on, all urine goes into the collection jug, including any passed during a bowel movement. Wake up and urinate at the same time the next morning into the jug to complete the collection. Keep the jug refrigerated when not in use, and bring it to the lab where blood will be drawn as part of the test.

The stages of CKD represent the degrees of kidney dysfunction, determined by your blood creatinine level and the resulting estimated glomerular filtration rate (eGFR), present for more than 3 months. Stage I (eGFR 90-120 ml/min) reflects normal or near-normal function with evidence of protein in the urine. Stage II (60-89 ml/min) often has no symptoms. Stage III (30-59 ml/min) is typically when you should be referred to a kidney specialist, and is subdivided into IIIA (45-59) and IIIB (30-44). Stage IV (15-29 ml/min) is when transplant referrals and dialysis-access discussions usually begin. Stage V (less than 15 ml/min) requires close follow-up to time the start of dialysis appropriately.

Your nephrologist will usually refer you to local transplant centers when your eGFR falls under 25 ml/min. Typical wait times for a deceased-donor transplant may be more than 4-5 years. If you have a potential donor, it may be possible to completely avoid dialysis and have a pre-emptive transplant when your kidney function drops further, usually to less than 15 ml/min.

When kidney function drops below 45%, you may require supplementation of the chemical erythropoietin. Erythropoietin is produced by healthy kidneys and stimulates the bone marrow to make blood. As kidney function deteriorates, less is made, so your blood count may drop and you may feel increasingly weak. Supplementation as Procrit or Aranesp can improve your blood counts and symptoms. These medications are provided in our office as a subcutaneous injection that you may receive every 2 to 4 weeks.

A significant amount of kidney function can be lost without the patient feeling unwell. Signs that there may be a kidney problem include red or brown colored urine (which might suggest blood); foamy or frothy urine (which could indicate protein); decreased quantity of urine; or swelling in the ankles. Poor energy, decreased appetite, nausea, itchy skin, a bitter taste in the mouth, and bleeding may be signs of severe kidney impairment. For many patients, blood test results are the first indication of a kidney problem.

Dialysis is a medical treatment for people with kidney failure that replaces many of the functions of healthy kidneys. In hemodialysis, the blood passes into an artificial kidney machine that filters wastes and removes fluid, then returns the blood to the body; it can be performed in a center three times a week or at home more frequently, and requires a vascular access such as a fistula. In peritoneal dialysis, typically done at home, a sterile liquid is instilled into the abdominal cavity where the lining filters wastes and excess fluid before being drained and repeated. Home hemodialysis is also available for patients who have someone able to help, after training at a dialysis center.