A person’s eGFR (estimated glomerular filtration rate) is the best indicator of how well the kidneys are working. An eGFR of 90 or above is considered normal. A person whose eGFR stays below 60 for 3 months or longer has CKD (chronic kidney disease). As kidney function declines, the risk of complications rises.

• Moderate Decrease in eGFR – 30 to 59
  At this stage of chronic kidney disease (CKD), hormones and minerals can be thrown out of balance, leading to anemia and weak bones. A doctor can help prevent or treat these complications with medicines and advice about food choices.
• Severe reduction in eGFR – 15 to 29
  The patient should continue following the treatment for complications of CKD (chronic kidney disease) and learn as much as possible about the treatments for kidney failure. Each treatment requires preparation. Those who choose hemodialysis will need to have a procedure to make veins in their arms larger and stronger for repeated needle insertions. For peritoneal dialysis, one will need to have a catheter placed in the abdomen. A catheter is a thin, flexible tube used to fill the abdominal cavity with fluid. A person may want to ask family or friends to consider donating a kidney for transplantation.
• Kidney failure (eGFR less than 15)
  When the kidneys do not work well enough to maintain life, dialysis or a kidney transplant will be needed.

Also, blood tests can show when substances in the blood are out of balance. If phosphorus or potassium levels start to climb, a blood test will prompt the doctor to address these issues before they permanently affect the person’s health.

Source: kidney.niddk.nih.gov – February 2009