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Draft: not yet reviewed by a clinician

Use this page to prepare questions for your care team. It does not replace their advice. Your own targets and doses come from your nephrologist, diabetes team and renal dietitian.

Dialysis days

No doses on this page

This handbook never gives insulin or medicine doses and never tells you to change one. Your prescriber sets every dose and every change, and writes down when to pause a medicine and when to restart it. A low blood glucose is always treated straight away: see Treating a low and Get help now.

In short

On hemodialysis, potassium, sodium and fluid build up between sessions, so they are judged over the whole gap, not just one day. The long weekend gap (Friday to Monday on a Monday–Wednesday–Friday schedule) is the riskiest time: deaths on the day after it were 22.1 vs 18.0 per 100 patient-years, and hospital stays for heart-rhythm problems roughly doubled (Foley 2011). Glucose often drops during a session, and most lows come within 24 hours of one, so check before and after, carry glucose tablets, and follow the insulin plan your team gives you for dialysis days (JBDS 2022).

Your numbers

Starting points, not your prescription

These numbers are typical starting points from guidelines. Your nephrologist, diabetes team and renal dietitian set your own numbers from your blood tests, urine output and medicines, and change them as your labs change. If your lab report or your team says something different, they win.
Allowance between sessions your per-day target × the number of days since the last session: with 2,500 mg potassium a day, the app compares a 3-day weekend gap with 7,500 mg. A low day still does not "bank" room for a high day, because potassium acts within hours (KDIGO 2024)
Fluid about 1,000 mL a day plus your urine output (DaVita)
Weight gain between sessions above 3.5 % of body weight is linked to death (Cabrera 2015); about 2.5 kg (5.5 lb) for 70 kg
When glucose drops it tends to fall during a session, lowest around the third hour; 3 in 4 lows happen within 24 hours of a session (JBDS 2022)

The app adds up potassium, sodium and fluid since your last session when you enter your dialysis days in the profile, and compares them with your per-day target × days (Targets and warnings).

Why lows happen on dialysis days

  • Dialysis removes glucose and insulin from the blood, and changes how insulin works, so glucose on dialysis days can be very different from other days (JBDS).
  • The dialysis fluid matters. UK guidance asks units to use dialysis fluid that contains glucose for everyone with diabetes on glucose-lowering treatment (JBDS). Ask your unit what yours contains.
  • Lows are common and easy to miss. In kidney failure, lows happen about twice as often as with normal kidney function, most within 24 hours of a session, and many people do not feel the warning signs (JBDS; JBDS 2022). A CGM alarm helps; confirm a CGM low with a fingerstick if your team asks you to.
  • Your team adjusts insulin for dialysis days. Ask them to write the plan down. Never change a dose on your own.

What to do

Before the session

  • Check your glucose before you leave home and again when you arrive.
  • Eat your usual meal at home if your unit does not allow food during the session.
  • Ask your unit about a carbohydrate snack. UK guidance suggests units offer 20–30 g of carbohydrate at the start if glucose before dialysis is under 126 mg/dL (7 mmol/L), and 10–20 g of a slower (low-GI) carbohydrate in the second hour, to stop glucose falling further in the third hour (JBDS 2022). Your unit's policy wins.

During the session

  • Tell the nurse straight away if you feel shaky, sweaty, confused or unusually tired.
  • Treat a low at once with glucose tablets or gel: they add no fluid (Dex4; Treating a low).
  • Keep any snack small. A big meal during dialysis can make blood pressure drop in the last hours of the session (JBDS).

After the session

  • Check your glucose before you drive or travel home, and again before bed.
  • Eat your next meal on time; the 24 hours after a session are when lows are most likely.
  • Take phosphate binders with meals and snacks the way your team prescribed.

Between sessions

  • Enter your dialysis days in the app so it can total the gap between sessions.
  • Weigh yourself every morning and write it down.
  • Keep potassium and fluid at the low end on Saturday and Sunday (for a Monday–Wednesday–Friday schedule).
  • Never skip or shorten a session (In-center hemodialysis).

Pack a dialysis-day bag

  • Glucose tablets or gel, at least two 15 g treatments
  • Your meter and strips, or your CGM reader or phone
  • Insulin and supplies, if your unit asks you to bring them (JBDS)
  • A snack your unit allows, with its carbohydrate written on it
  • Phosphate binders, if you eat at the unit
  • Your medicine list and your team's phone numbers
  • A warm layer and something to read or listen to

Example: the long weekend gap

The hemodialysis sample menu is built for a 70 kg adult with a 2,500 mg potassium and 1,500 mL fluid starting allowance. Its weekend looks like this (FDC):

Potassium Fluid (drinks and liquid foods)
Saturday 2,029 mg 592 mL
Sunday 1,660 mg 473 mL
Two days together 3,689 mg 1,065 mL
Two days' allowance 5,000 mg 3,000 mL

The weekend stays well inside the allowance on purpose, because the gap is a day longer than the others. The 1,065 mL of fluid is about 1.1 kg (2.3 lb) on the scale, plus the water in solid food (DaVita); the 3.5 % line for 70 kg is about 2.5 kg. If your Monday weight is often near your team's limit, Saturday and Sunday are the days to cut back on fluid and salt.

Ask your care team

  1. Can I eat during my session? What snack is allowed, and when?
  2. What should I do about insulin on dialysis days? Please write it down.
  3. Does my dialysis fluid contain glucose?
  4. What is my fluid allowance and my weight-gain limit between sessions?
  5. Which of my medicines should I take after dialysis rather than before?

Get help now if…

  • You miss a session, or gain more weight than your alarm number: call your unit today.
  • Your access bleeds after you get home: press firmly on gauze with two fingers. Call 911 if the bleeding is heavy or spurting, has not stopped after 10–15 minutes of firm pressure, or starts again (AKF).
  • Blood ketones of 3.0 mmol/L or more, or any ketones with vomiting, deep fast breathing or fruity breath: call 911. With kidney failure these signs count even when ketones are under 3.0 (2024 consensus).
  • Chest pain, severe breathlessness, fainting, a very slow or irregular pulse, or a low you cannot treat yourself: call 911 (or your local emergency number). See Get help now.

Sources

Not yet reviewed by a clinician. Facts and sources last checked 2026-10-06.