Medical & Encyclopedia Symptoms of a Failing Kidney

Kidney failure, or renal failure, can be classified as either chronic or acute. Acute kidney failure occurs when the kidneys suddenly fail, which can be due to heart failure, circulatory shock, drugs, toxic chemicals, obstruction, or kidney disease. Chronic kidney failure is trouble that builds or persists over a long period of time.

Urinary Symptoms

In the early stages of chronic kidney failure, there is an increase in frequency and volume of urine. This often causes a person to need to urinate several times at night, due to the kidneys inability to absorb water, which also causes an increase in urine volume. In acute kidney failure, however, there can be decreased urine output.

Blood Symptoms

Chronic kidney failure causes increased levels of urea, a metabolic waste product, in the blood, according to the "Merck Manual of Medical Information." In acute kidney failure, blood levels of both urea and creatinine increase, as do concentrations of phosphate, parathyroid hormone, and potassium (slightly). Meanwhile levels of vitamin D and calcium decrease. Blood acidity is also increased.

Digestive Symptoms

The buildup of toxins caused by chronic kidney failure can have many effects on the digestive tract, including loss of appetite, nausea, vomiting, inflammation of the lining of the mouth, and an unpleasant taste in the mouth. These symptoms may lead to malnutrition and weight loss. Intestinal ulcers and gastrointestinal bleeding are also common.

Skin-Related Symptoms

In chronic kidney failure, the skin may turn yellow-brown. Occasionally urea concentration is so high that it crystallizes from sweat, forming a white powder on the skin, known as uremic frost. In some cases, there is uncomfortable generalized itching. In acute kidney failure, some people develop skin rashes.

Secondary Conditions

Due to the kidneys’ inability to eliminate excess salt and water, high blood pressure often develops, which can cause stroke, heart failure or brain malfunction, resulting in convulsions, or seizures. Acute kidney failure often causes pulmonary edema, according to Dr. Benjamin F. Miller, author of "Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health."