Frequently Asked Questions
What do the kidneys do?
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.
Why did my doctor send me to a kidney specialist?
“Your creatinine is elevated.”
Creatinine is a substance in the blood that is checked in routine lab tests by your doctor. It is a product of muscle breakdown and everyone generates a set amount of creatinine on a daily basis depending on muscle mass. The creatinine levels in the blood reach a steady state, depending on how well the kidneys are getting rid of it. Nephrologists test creatinine levels as an indicator of kidney function; levels that are higher than normal may reflect kidneys that are not working up to par.
“Your eGFR is decreased.”
Many labs are reporting estimated glomerular filtration rate (eGFR) in addition to creatinine levels. The result of this test is calculated from other blood tests (including creatinine) and it estimates how well the kidneys filter the blood. A reduced eGFR may indicate a reduction in kidney function.
“Your blood pressure is too high.”
The kidneys are fundamental in controlling your body’s blood pressure. In some cases, high blood pressure is an indication of an underlying kidney disorder. Uncontrolled high blood pressure can lead to kidney injury; treating high blood pressure is an important part of keeping your kidneys healthy.
“You have protein in your urine.”
The primary function of your kidneys is to filter and purify your blood. Normally protein in your blood is held back and none of it is supposed to get into the urine. Having protein in the urine is usually an indicator of damage to the filters in your kidneys. Many different processes (the most common is diabetes) can cause the filters to become leaky.
“You have blood in your urine.”
Blood in the urine (hematuria) may be present if the urine is discolored red or brown. Small traces of blood, which can only be seen by a microscope, can also be detected on routine analysis of urine ordered by your doctor. The presence of blood in the urine may be a sign that the kidneys are injured.
“You have kidney stones.”
Kidney stones result from unusually high amounts of substances normally present in the urine, such as calcium and uric acid, crystallizing and growing into a solid structure within the kidney. There are many elements including diet, fluid intake, and imbalances in urine chemistry that can predispose you to kidney stones. Evaluation and treatment by a nephrologist can identify risk factors and reduce the likelihood of stones from forming in the future.
How do I collect a 24-hour urine specimen?
At times during an evaluation of a kidney problem, we will ask you to collect a 24-hour urine specimen. This test can be used to measure kidney function and to determine the amount of various substances present in the urine, such as protein, calcium, and uric acid.
For convenience it is recommended that you collect the 24-hour urine sample on a day that you will be home all day. When you wake up in the morning that you are to start the test, you are to urinate into the toilet and flush this urine. Note the time as the start of the collection. From this time on all urine goes into the collection jug. If you have a bowel movement, attention should be paid so that any urine passed goes into the jug. You should wake up and urinate the next morning at the same time you did the first day to start the test. This second morning urine goes into the jug and the collection is now complete. You should keep the jug in the refrigerator when it is not being used. When the sample is complete it should be brought to the lab where blood will be drawn as part of the test.
What are the stages of CKD?
The stages of CKD represent the degrees of kidney dysfunction. This is determined by your blood creatinine level, which is then used to determine your estimated glomerular filtration rate (eGFR.) This abnormal value must be present for more than 3 months to denote a chronic process. Evaluation by a nephrologist may help with the control of risk factors for kidney disease. Medications may also be considered which could potentially help slow the progression of kidney disease.
Stage I– eGFR 90-120 ml/min, reflects normal or near normal kidney function but with evidence of protein in the urine.
Stage II– eGFR 60 to 89 ml/min. Often there are no symptoms of kidney disease at this stage.
Stage III– eGFR 30-59 ml/min. Typically you should be referred to a kidney specialist when your kidney function drops to this level. There may be issues at this stage including fluid retention, anemia, elevated potassium and phosphorus levels, an imbalance in the acid-base status, and weakening of the bones. Stage III is further subdivided into stage IIIA which represents an eGFR at 45-59 ml/min, and stage IIIB which represents an eGFR 30-44 at ml/min.
Stage IV– eGFR 15 to 29 ml/min. The problems which begin at stage III may only worsen in stage IV kidney disease. Referrals to transplant centers are usually recommended at an eGFR less than 25 ml/min. Additionally, discussions about the various modalities of dialysis are had along with the appropriate referrals for dialysis access placement.
Stage V– eGFR less than 15 ml/min. Patients usually need close follow up with their nephrologist at that time to ensure proper timing for initiation of dialysis so that complications of progressive renal failure can be avoided. Symptoms which indicate the need to begin dialysis include lack of appetite, nausea, vomiting, increased fatigue, hiccups, and metallic taste in your mouth. With proper education and preparation, dialysis can be initiated as an outpatient and hospitalizations can be avoided.
When should I get evaluated for a kidney transplant?
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, then 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.)
What is Aranesp (or Procrit)? Do I need it?
When kidney function drops below 45%, you may require supplementation of the chemical erythropoietin. Erythropoietin is produced by healthy kidneys; its function is to stimulate the bone marrow to make blood. As kidney function deteriorates, less and less erythropoietin is made. As a result, your blood count may drop and you may develop symptoms such as increasing weakness. Supplementation of erythropoietin either as Procrit or Aranesp can improve your blood counts and symptoms. These medications are provided in our office as a subcutaneous (under your skin) injection which you may have to receive every 2 to 4 weeks.
What are the symptoms of kidney failure?
Unfortunately, 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 the presence of blood; foamy or frothy appearing urine, which could indicate protein in the urine; 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 and symptoms of severe kidney impairment. For many patients, blood test results are often the first indication of a kidney problem.
What is dialysis?
Dialysis is a medical treatment for people with kidney failure. Dialysis replaces many of the functions of healthy kidneys. There are several types of dialysis: In hemodialysis the body’s blood passes into an artificial kidney machine that filters it of wastes, removes fluid, and then returns the blood back to the body. Hemodialysis can be performed in a dialysis center three times a week or at home more frequently. Hemodialysis requires a means to the bloodstream, termed a dialysis “access.” The most desirable access is a fistula, a surgical connection between a vein and an artery in the arm. Two needles are placed into the fistula for each dialysis treatment, one to remove blood and the other to return the purified blood.
Another type of dialysis is peritoneal dialysis, which is typically done at home. In this type, a sterile liquid is instilled into the abdominal cavity where the linings of the intestines filter the blood of wastes and excess fluid into the liquid. The liquid is then drained and the process is repeated. This type of dialysis can be done during the daytime and/or at nighttime with the assistance of an automated machine. A catheter or hollow tube is surgically placed into the abdominal cavity and exits through the skin to enable this type of dialysis.
Home hemodialysis is available for patients who have someone in their home willing and able to help. Patients are trained by medical professionals to do dialysis treatments at home. Training is conducted at a dialysis center and takes up to eight weeks. Home hemodialysis uses a dialysis machine to clean the blood. The patient’s blood flows from his or her vascular access through a dialysis machine to be cleansed of extra waste and fluids and sent back into the body. Many home dialysis patients dialyze more frequently than in-center patients. The more frequent treatments get blood cleaner and leave patients feeling better.