Dialysis Basics for non-medical people

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I feel like I should start this with a disclaimer that I'm not a medical professional. So here: I'm not a medical professional, I'm “just” a patient. I've spent a total of about six years on dialysis, so I'm only sharing from my own experiences and understanding. This is not medical advice, it's a way for me to explain some terms that people may not be familiar with, and that I'll use often in the coming months and years.

Dialysis Overview

I'll be talking about two types of dialysis; there's a third one that exists, but I'm not familiar with it, so I'm not going to go there. The ones I'll cover are hemodialysis and peritoneal dialysis, shortened to “hemo” or “PD” The third option at at-home hemo, and you can read about it here.


This is most likely what you picture when you imagine dialysis. It's the one you see on medical shows on TV, and is the most common modality for dialysis patients in the US, by a vast majority. Of the ~470,000 Americans on dialysis, 93% of them choose hemo. (Source)

Hemo is done in a clinic, on a set schedule. Generally, it's done three days a week, for about four hours at a time. I'm currently on hemo, a M-W-F schedule, 5:30-9:30 pm. In short, hemo removes blood from your body, “washes” it, and then returns it to your body. The washing process removes waste products and excess fluid, in varying amounts depending on gain.

You have what's called a “dry weight,” which is how much you weigh when you have no excess fluid in your system. Doctors will often set a goal to limit how much you gain in between treatments, it's usually a couple of kilograms. This is why dialysis patients are often on a fluid restriction diet, where they have to limit how much they take it, because too much fluid will dilute the blood and cause blood pressure to increase.

When I get to the clinic, I weigh myself and get situated at my station. A blood pressure cuff is placed on my arm, and my standing BP is taken. The cuff will stay on for the duration of treatment, going every 30 minutes.

The clinic is staffed by nurses and techs; the nurse is an RN and does the work of actually connecting me to the machine. Techs are there to clear alerts during treatment, and generally provide support to patients and RNs.

As an acute dialysis patient, my access for dialysis is a subclavian catheter implanted near my collarbone. If I were going to be on dialysis long term, I'd have a graft or fistula put in my arm, allowing them to use large bore needles, like a big IV, for access. Learn more about fistulas and how they work here.

The actual process of dialysis is pretty straightforward. Blood goes from me, through the filter (aka artificial kidney or dialyzer) and then is returned to me. Here's what the machine looks like; that white thing on the right side of the pic is the dialyzer. If you're interested, you can see what the machine in use looks like; it's stashed for people who don't want to see blood, but it's not grisly at all, I promise.

So I'm hooked up to this machine for hour hours, as my blood is scrubbed and cleaned. I can eat and drink while it's going, and ridiculous silver lining is how much Sonic-style nugget ice I can have from the ice machine.

That covers the basics on hemo; next I'll talk about PD.

Peritoneal Dialysis

This is my preferred dialysis; it's done at home, every night while I'm sleeping, so I have more control over my life, and because it's happening more often, it more closely mimics kidney function, so instead of the ups and downs of going three days between treatments with hemo, it's every day and more continuous.

I have an analogy I always use to explain how PD works, so I'll lay it out here. The peritoneum is the lining of your abdominal cavity; pretend it's a bucket. Now put a bunch of boulders in the bucket. The boulders are your organs. Stomach, liver, intestines, lungs, those stupid useless kidneys. Fill the bucket with boulders. The bucket's full, right? Nope. Now take some sand and pour it in the bucket. NOW it's full. The sand is the PD solution, which is a dextrose solution in varying strengths.

Your body basically functions by osmosis, and it always wants to keep things in balance. Nutrients are absorbed by your intestines, oxygen is absorbed by your lungs, etc. When you fill your abdomen with PD fluid, your body looks at that solution, and looks at the blood in your body, and wants to even those two things out, so it starts dumping waste products into the PD solution, and taking dextrose to balance everything out.

The PD fluid is left in for a few hours, so it evens everything out, then it's drained and discarded, taking all the waste products with it. And repeat continuously throughout the night. The “machine” is basically just a pump; it's shown below. Bags of solution go on top, and tubes feed through a pump on the side. While I sleep, the machine fills me up, lets it sit, drains it out and then refills it.

It's possible to do PD without a machine, and just use gravity. For me, I've done PD exchanges while camping, while driving, it allows quite a bit of flexility and like I said before, control over my own life.

The access for PD is a catheter that's surgically implanted into the abdomen, next to and below the belly button. It's about 6″ long, but very simple. I'm currently hoping to schedule this procedure soon, so that I can get switched to PD sooner rather than later.

Pros and Cons

There are advantages and disadvantages to each modality, I'll go over them here.

Hemo takes a lot of time that you can't do anything else; PD lets you multitask while you're sleeping, giving you back a whole lot of time. For a younger dialysis patient (I was only 24 when I started this journey) it's no good to spend 13-15 hours a week surrounded by old, sick people.

PD takes up a lot of space in your home; you need to do 4-5 exchanges a day, and the bags of solution are big, like the size of a large bag of chips. You're supposed to keep a 2 week backup supply on hand at all times, and it can take up a ton of space. (Our old house had the perfect layout for this; I actually have to figure out how this will work in our current home)

PD has a scary infection risk, called peritonitis. It's an inflammation of the peritoneum, and it's simply the worst pain I've ever felt in my life. You can read my blog post from the one time I had it here.

Dietary restrictions tend to be lessened on PD; like I said before, it more closely mimics natural kidney function because it's more often, so this leaves a little more wiggle room with the restrictions. Not so much that I can like eat cheese, but it allows more options for sure.

Hemo, when done long term, means that large needles are stuck into your arm multiple times per week. I was only on hemo with a graft for about 3 months, and I still have visible scars from the needles on my arms. PD isn't directly blood; there are no needles, and the catheter is painless once it heals.

This pro/con is probably pretty biased; I can totally manage PD better, and as long as I have to be on dialysis, I'd rather be on PD. If you found this post because you're looking at starting dialysis, I hope it was helpful to you, and feel free to reach out if you have more questions or anything. If you're one of my amazing friends or readers who just want to know, thanks for caring, and I hope this has given you a useful look at the two most common ways dialysis is done.

As always, don't hesitate to leave your questions in the comments below or on my Facebook page. I'll do my best to answer them!




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