According to the National Kidney Foundation (NKF), 1-in-9 Americans has kidney disease. About 26 million American adults have chronic kidney disease, and millions more are at increased risk. Lack of routine screening makes this problem worse because people tend to be diagnosed later than necessary. Greater awareness of the symptoms and causes of abnormal function may result in prolonged kidney life.
Symptoms
Regardless of the cause, the initial symptoms of abnormal kidney function are often the same for many patients. Many patients are unaware that anything is wrong until a urine specimen given for a life insurance test or military health check comes back positive for protein or blood. Sometimes a minority of these patients even make it almost all the way to renal failure without complaining about anything more serious than fatigue. Other patients have more dramatic symptoms, such as scarlet-colored urine, edema and serious headache. Regardless of the severity of the symptoms, almost all patients experience some degree of hypertension, or high blood pressure.
Acute or Chronic
Abnormal kidney disease can be chronic or acute. The disease is acute if it resolves by itself. The disease is chronic if it does not resolve itself. Unlike acute disease, chronic disease can progress to end state renal disease, commonly referred to as ESRD. In such cases, kidney function may steadily decline over a period of years or even decades.
These categories are not necessarily exclusive. Chronically ill kidney patients can also experience acute bouts of disease that resolve to whatever their pre-existing baseline status was. Such episodes are often misinterpreted by patients who mistakenly believe they are getting better.
Causes
One of the most common causes of abnormal kidney function is diabetes. According to the National Institute of Diabetes, Digestive and Kidney Diseases, diabetes accounted for 43.8 percent of all renal failure in 2005.
The second leading cause of loss of kidney function is hypertension. This is not surprising when you consider that kidneys are largely composed of vascular tissue. High blood pressure can be a relentless scourge, destroying blood vessels in the kidneys.
Glomerular disease is another major cause of abnormal kidney function. Glomerular diseases involve scarring of the microscope filters of the kidney called glomeruli. Glomerular diseases include IgA nephropathy, focal segmental glomerular sclerosis (FSGS), membranoproliferative glomerular nephritis (MPGN), membranous nephropathy and many others.
Diagnosis
Diagnosing the cause of abnormal kidney function can take several months and involve renal biopsy, renal ultrasound, blood work, urinalysis and other tests.
Most glomerular diseases cannot be conclusively diagnosed without biopsy. Although renal biopsy is a minor procedure that usually does not require an overnight stay in the hospital, it is not with a small degree of risk. In some instances, symptoms may not be severe enough to merit the risks associated with biopsy. In other instances, the kidney may be so scarred that it is impossible to tell why function is abnormal.
Treatment
Abnormal kidney function is treated symptomatically. Treatment often focuses upon lowering blood pressure and minimizing urine protein. Other symptoms, such as anemia, hyperkalemia (excess potassium) and bone problems, are treated as required. In some instances, a restricted diet may be indicated to compensate for the kidney's inability to filter impurities from the blood.
Some of the drugs given to lower blood pressure are also effective in lowering protein levels in the urine. In other instances, steroids or other agents may be used.
