Renal failure, also called kidney failure, occurs when your kidneys fail to filter waste from your body. Medical researchers classify renal failure into two types: acute and chronic. Acute renal failure occurs suddenly, and according to the Mayo Clinic, often follows surgery or injury that causes an abrupt interruption of the flow of blood to the kidneys. Chronic renal failure happens gradually, because of such conditions as diabetes and hypertension.
Waste Product Symptoms
Acute renal failure can reduce the amount of urine you produce. It also may cause you to retain fluids, because they cannot be processed out of your body. This may cause swelling in your feet, ankles and legs. Symptoms of chronic renal failure also include a reduction in urine output, even to the point of not being able to urinate. It also may cause your urine to darken in color. This form of failure also may cause your stools to be tar-like or bloody.
Fatigue
Both the acute and chronic forms of renal failure can cause you to become fatigued. This means you may feel overly weak in your body and limbs. Most people only experience this when they are very active, but in this case, the fatigue will not be a result of physical activity.
Seizures and Coma
Specific to acute renal failure are the severe symptoms of seizures and coma. The cessation or reduction of your kidney function can send toxins throughout your body. This can cause your central nervous system to react. These symptoms are not associated with chronic renal failure, the Mayo Clinic reports.
Digestive Symptoms
Chronic renal failure can produce symptoms that affect your digestive system. It can make you nauseous, and you may vomit. You also may lose your appetite, or you may only feel able to eat a small amount. Chronic renal failure also can cause you to experience a sudden unexplained increase or decrease in your weight.
Mental Symptoms
Both chronic and acute renal failure can cause problems for your brain. Both can cause mental confusion or a reduction in the level of your mental sharpness. Chronic renal failure also can cause headaches.
