Why do you retain water when you have renal failure?

my friends dad is going through renal failure and he told me that his legs are swollen because of water retention.
he was also talking about high blood pressure .can someone explain to me why this all happens??
Answer:
The kidneys are made up of lots of tiny filters/sieves that clean and filter all of the blood in your body. Normally, 100% of the filters are working. But if some of the filters are damaged and only, say, 20% of them are working, the body tries to compensate for this by increasing the blood pressure so it can force more blood through the 20% that are left. This is why blood pressure goes up when kidneys fail - because the body is trying to force all the blood through the few filters that are still working.
Because the filters aren't working, the body also isn't able to get rid of as much sodium in the urine as it usually would. As the level of sodium builds up in the body, water stays behind as well and this excess water causes swelling of the legs and ankles.
Best wishes for your friends Dad!

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Renal failure means that the kidneys are failing. The kidneys are responsible for flushing all of the toxins out the body and cleansing the blood. When the kidneys fail, the body can't do this. The body begins to retain fluid and common places are the feet, legs, and hands. The excess fluid raises the blood pressure because the heart has to work a lot harder to pump the blood through the body.

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Renal failure means that the kidneys are shutting down. That means they are not getting rid of the fluids through urination and because of it the fluids are staying in the body and going else where. ankles legs where ever. When you retain water/fluids your blood pressure also goes up. That is why when you have high blood pressure they also put you on a diuretic so it helps to get rid of excess fluids.

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when you have renal failure your kidneys are not filtering the toxins out of your body. when i had failure i stopped peeing all together. that is why you go on dialysis to filter out the toxins out of your body.he could ask his doctor to give him lasic, that will help the swelling. that is just part of renal failure.

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