Hypertension and heart disease can cause damage to the kidneys. So can diabetes, kidney stones, some cancers, prostate enlargement that blocks the urinary tract, and a number of rarer conditions: vesicoureteral reflux, urine backing up into the kidneys; glomerulonephritis, an inflammation of the parts of the kidney used for the organ’s filtering function; and polycystic kidney disease in which cysts develop on the kidneys. Between these conditions, recurrent kidney infection, and plain bad luck, kidney disease affects ten percent of the global population.
Sometimes, the source can e hard to pin down. A chemical called domosic acid, produced in the ocean by algae and frequently found in shellfish, has long been known to be a neurotoxin, damaging the brain, at high doses, but was believed to be safe enough in smaller quantities. Now, however, scientists have found that these much lower amounts are nonetheless high enough to cause toxicity in the kidneys, which, filtering the blood, get the brunt of these amounts.
Unfortunately, left untreated, kidney disease can be fatal, either through the kidney itself failing or when the damage to the kidney and consequent diminished function leads to cardiovascular disease. That is why early detection is so important. The good news is that tests for kidney disease are simple and reliable, even if there are no symptoms. A doctor may test a patient’s blood or urine, looking for telltale signs of damage, or an ultrasound scan is used to detect changes in the size or density of the kidneys that point to health problems. Testing is particularly important not only for early detection, but because the symptoms of kidney disease—persistent itching nausea, vomiting, loss of appetite, and changes in the amount and quality of urine—could be caused by a number of other conditions as well.
Knowing the cause is also important to proper treatment, because treatment often involves addressing the cause of the damage. In addition, dietary changes may be recommended so as to give the kidneys less work to do. Other treatments are directed at the symptoms. In severe cases, when one or both kidneys has failed entirely, a transplant or dialysis with a machine that functions as an artificial kidney may be necessary.