Reality TV host Nick Cannon was hospitalized earlier this month in Aspen, Colo., where he was vacationing with his wife, singer/actress Mariah Carey. Carey caused a stir when she tweeted that Cannon was being treated for “mild kidney failure.” Doctors have no such designation for kidney failure patients, so it’s unclear what Cannon’s health concerns entailed.

According to the American Urologic Society, kidney failure can be classified as either acute or chronic. Acute kidney failure occurs when the kidneys abruptly stop filtering waste products from blood. Patients experience symptoms such as fluid retention, internal bleeding, confusion, seizures and coma. Chronic kidney failure develops slowly with very few symptoms in its early stages. Once kidney function drops below 20 percent of its normal capacity, a variety of symptoms can emerge, including weight loss, anemia, nausea or vomiting, decreased mental function and a yellowing or browning of the skin.

Treatments for kidney failure include dialysis, in which the blood is filtered using an external machine, or a kidney transplant.

— Markian Hawryluk, The Bulletin

Sources: American Urological Association, Journal of the American Medical Association