Updated

Chronic kidney disease (CKD) is caused by a kidney's inability to filter waste and unnecessary fluids. Without a functioning kidney, excess fluid accumulates, which can lead to a plethora of complications, including anemia, nerve injury and brittle bones. The National Kidney Foundation reports that 26 million American adults have chronic kidney disease, and millions of others are at increased risk.

Causes
Two-thirds of all CKD instances stem from diabetes or high blood pressure. With diabetes, one's blood sugar is dangerously high, which damages numerous organs, including the kidney.

High blood pressure is when the heart pumps out lots of blood, usually to counterbalance narrow arteries. The increased pressure in the blood stream can damage the kidney, leading to CKD. Also, if one has CKD from a different cause, the disease can cause high blood pressure.

The National Kidney Foundation says other factors can spur CKD: urinary infections, obstructions, lupus, malformations that developed as a fetus, inherited diseases and glomerulonephritis.

Symptoms
Since CKD damages kidneys gradually, symptoms manifest slowly over an extended period. Furthermore, the kidneys are adaptable, so symptoms might not appear until they have irreparable damage. To make matters worse, the disease's warning signs could be indicative of other diseases.

According to the Mayo Clinic, symptoms include appetite loss, hiccups, muscle cramps, fatigue, nausea, shortness of breath, vomiting, insomnia, persistent itching and chest pain.

Diagnosis
Doctors can understand a kidney's ability to function by determining your glomerular filtration rate (GFR). A doctor can figure out this rate by administering a blood creatinine test and taking age, race and gender into account.

Michael A Kraus, a nephrologist and professor of clinical medicine at The Indiana University School of Medicine, pointed out that African-Americans are at five to six times higher risk of developing the disease than Caucasians.

An imaging test, such as an ultrasound or CT scan, can provide a picture of the kidneys and urinary tract. This will let the doctor know the size of the kidneys and whether a kidney stone or tumor is present.

With a biopsy, doctors determine the specific type of kidney disease and how much damage has transpired.

Treatment
Treatments vary based on the underlying cause.

Ellie Schlam, vice president of communications at the National Kidney Foundation, says, "For those with kidney disease, it's important to manage blood pressure and blood sugar through lifestyle and medication."

Doctors may prescribe medications to lower blood pressure and cholesterol, relieve anemia and swelling, and protect fragile bones.

CKD almost always develops into end-stage renal disease, loss of sustainable kidney function, which necessitates renal replacement therapy. Survival rates for this disease are very poor. Kraus explained that 50 percent of patients starting on dialysis today will be dead by the end of three years.

Schlam said, "Dialysis, or an artificial kidney, can do the work of the kidney for those whose kidneys have failed." Dialysis removes waste from the blood when the kidney can no longer function.

Kraus says patients with end-stage renal disease should understand the options available to them. "They should be educated in transplantation, home hemodialysis, peritoneal dialysis and they shouldn't just accept in-center dialysis."