Thursday, 24 January 2008

A little bit about dialysis….

I am on Haemodialysis (HD) 3 times a week for three hours. So firstly I get to the unit around 5.15pm and am usually on the machine by 5.45pm. Before going on the machine I have to take my blood pressure and weigh myself because as well as cleaning the blood the dialysis machine also removes excess fluid, The amount of fluid removed depends on your dry weight. Mine at the minute is 66kg and I remove roughly 2.5litres every dialysis session. This part of the process is called ultrafiltration.

Haemodialysis removes waste products from the blood by passing it out of the body, through a filtering system called a dialyser and returning it, cleaned, to the body. I have two needles inserted into my fistula which is a surgically enlarged vein (located in my upper arm).This provides access to the bloodstream for haemodialysis. The fistula buzzes all the time which is a good thing as this means the blood is flowing through it freely.

Click here to see how a fistula is made and used!

The needles that are used for dialysis are a bit painful when they are inserted but during the dialysis session I can’t feel a thing. I usually just watch the tele (all the soaps) whilst I’m on the machine as this passes the time. I would go to sleep if I could but there is constant hustle and bustle and machines beeping! The machine beeps if I accidentally lean on the tubes (containing the blood) or most importantly when the dialysis has finished.

During dialysis…

While in the filtering system the blood flows through tubes made of a membrane that allows the waste products (which are much smaller than blood cells) to pass out through it. The waste products pass through the membrane into a dialysis solution (dialysate), then out of the machine. The "clean" blood is carried on through and returned safely to the body.

This happens over and over again throughout the dialysis session. Each time the "clean" blood is returned to the body, it picks up more waste products from the cells it circulates through, and brings these newly-collected toxins back to the dialyser to be removed.

Fresh dialysate is passed through continuously to make the rate of the cleaning process as fast as possible.

Click here to see an animation of dialysis in action…

and click here to see definitions of the terms in black.

Next post….

Fluid and diet restrictions … exciting stuff!!!


  1. great blog - i learnt loads i didn't even know there! xx

  2. hi Holz its jenjen... I'm super excited to have a new blog every day

  3. Wow that was dead interesting reading that, i feel like i know a bit more about it now! love you!x

  4. Hi Holly. Loving your blog very informative. Amazing the number of diffrent tablets out there for renal patients im on a totally difrent regime of the to you. Keep up the ood work Tom x