Under normal circumstances, your kidneys help maintain your body’s fluid balance by collecting excess fluids in your blood and excreting them in your urine. However, if your kidneys fail, they will stop performing this vital function and fluid will build up in your kidneys and body. People with kidney failure typically need to undergo a procedure called dialysis, which uses artificial methods to eliminate the fluids and waste normally handled by the kidneys.
Every 24 hours, your kidneys filter about 200 quarts of the fluid circulating through your bloodstream, according to the National Kidney Foundation. Roughly 198 quarts of this fluid get passed back to your body after your kidneys remove any accumulated wastes; the remaining 2 quarts of liquid help flush out these wastes in your urine. When your kidneys fail, they no longer effectively pass this waste-filled fluid out of your body. Instead, fluid and waste build up and trigger widespread changes that include swelling and harmful alterations to blood pressure control, bone health and your body’s ability to produce red blood cells.
Your kidneys can fail slowly over time or rapidly in a short period of time. Slow, or chronic, kidney failure has potential causes that include diabetes, high blood pressure, heart disease, inherited and acquired kidney disease, urinary blockages and infection. Rapid, or acute, kidney failure has potential causes that include direct injury, burns, infection, dehydration, surgery, clotting in the blood vessels that supply the kidneys, autoimmune kidney disorders, urinary blockages and certain pregnancy complications. While problems associated with acute kidney failure can develop very quickly, problems associated with chronic kidney failure may only appear after you develop advanced kidney damage.
Dialysis comes in two basic forms. During a procedure called hemodialysis, your blood is passed through a device called a dialysis machine that removes wastes and excess fluid, then returns the cleansed blood to your body. During a procedure called peritoneal dialysis, doctors use a catheter to insert a specialized fluid called dialysate into your abdomen, or peritoneal cavity; this fluid pulls waste and excess fluid out of your bloodstream and collects it for disposal. People on hemodialysis typically undergo the procedure three times a week at a doctor’s office or clinic. People on peritoneal dialysis typically undergo the procedure every day while at home.
If you undergo hemodialysis, excess fluid will only be removed from your system periodically. As a result, your doctor may ask you to restrict your fluid intake in order to avoid fluid buildup between dialysis sessions. Since people undergoing peritoneal dialysis have their blood cleansed more often, they can usually safely drink higher amounts of fluid. However, fluid restrictions vary from person to person, and your doctor will determine how much fluid you can drink without endangering your health. If you build up excess fluids while on dialysis, potential consequences include shortness of breath, high blood pressure, heart problems and sudden blood pressure drops.