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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.

Sick days with type 1 diabetes and CKD

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

Illness, vomiting and diarrhea can push glucose and ketones up fast, even when you eat little. With type 1 diabetes that can lead to diabetic ketoacidosis (DKA). With kidney disease, losing fluid can also hurt the kidneys and change your potassium. Never stop your basal insulin, check glucose and ketones often, and follow a sick-day plan your team wrote down before you got ill. The plan says which of your medicines to pause, and exactly when to restart them (ADA 2026 §6; KDIGO 2024, practice points 4.3.2–4.3.3).

Your numbers

When to check:

Check How often when you are ill
Glucose at least every 4 hours, day and night (CDC); a CGM helps
Ketones when you feel ill, miss insulin or have symptoms, especially if glucose is above 200 mg/dL (ADA 2026 §6); then as your plan says
Check How often when you are ill
Glucose at least every 4 hours, day and night (CDC); a CGM helps
Ketones when you feel ill, miss insulin or have symptoms, especially if glucose is above 11.1 mmol/L (ADA 2026 §6); then as your plan says

What blood ketones mean (the same numbers in every country):

Blood ketones What to do
under 0.6 mmol/L normal; keep checking glucose
0.6–1.5 mmol/L follow your sick-day plan; check again in 2 hours. If you are also ill, call your team
1.6–2.9 mmol/L call your diabetes team now. If you cannot reach them quickly, or you are vomiting, go to the emergency department
3.0 mmol/L or more emergency: call 911 or go to the emergency department

Sources: NHS; ADA (the American Diabetes Association advises emergency care at 1.6 mmol/L or more). DKA is confirmed with blood ketones of 3.0 mmol/L or more and acid in the blood (2024 consensus). UK dialysis guidance also says that blood ketones above 3.0 mmol/L need medical assessment straight away (JBDS 2022).

Urine strips are less exact. NHS advice reads + as roughly 0.6–1.5 mmol/L, ++ as roughly 1.5–3.0 and +++ as above 3.0 (NHS ketone advice). This handbook treats ++ or more like 3.0 mmol/L and says get emergency help, because the 2024 consensus counts urine ketones of 2+ or more toward DKA (2024 consensus). A blood ketone meter is better: in a trial, blood checks halved hospital and emergency visits compared with urine strips (ADA 2026 §6).

Ketones are the deciding number with kidney disease

DKA is partly diagnosed by a low bicarbonate. Many people with advanced kidney disease have a low bicarbonate anyway (Bicarbonate), so that number does not tell you much. Watch your ketones and how you feel. People with kidney failure often have lower ketone numbers in DKA than other people (2024 consensus, Table 4; JBDS 2022). On dialysis, the usual signs, such as thirst, dry mouth and deep fast breathing, may be missing (JBDS 2022). Trust symptoms like vomiting, belly pain, drowsiness or fruity breath even if the meter reads under 3.0.

What to do when you get ill

  • Keep taking your basal insulin, even if you are not eating. Illness often raises insulin needs. Your plan says how to adjust (ADA 2026 §6; NHS).
  • Check glucose at least every 4 hours, including at night (CDC).
  • Check blood ketones and act on the table above. If you make little or no urine, urine strips will not work: use a blood ketone meter (JBDS 2022).
  • If you cannot eat meals, take carbohydrate in small amounts through the day. CDC suggests about 50 g every 4 hours (CDC). Kidney-friendly choices are below.
  • Take your sick-day plan out and follow the medicine part: pause only what it says to pause.
  • Write down the time and result of every check, and what you took. The app's log works for food and drinks (Logging food).
  • Call your team early, not late. Use the after-hours number if needed.

Medicines on sick days

When you lose fluid through vomiting, diarrhea or fever, some medicines can harm the kidneys, drop your blood pressure or raise potassium. KDIGO lists medicines that sick-day plans often pause: sulfonylureas, ACE inhibitors, diuretics ("water pills"), metformin, ARBs, NSAIDs and SGLT2 inhibitors (KDIGO 2024, practice point 4.3.2). Metformin and sulfonylureas are rarely used in type 1 diabetes.

Medicine Why it matters when you are dehydrated What to ask
ACE inhibitor or ARB can lower blood pressure, strain the kidneys and raise potassium "Should I pause it while I am vomiting? When do I restart?"
Diuretic (water pill) removes more fluid when you are already low the same question
NSAID (ibuprofen, naproxen) harms the kidneys; best avoided anyway "What can I take for fever or pain instead?" (Medicines to avoid)
SGLT2 inhibitor (not established in type 1; see Kidney-protecting medicines) raises the risk of DKA, even with normal glucose (Farxiga label) "Do I stop it as soon as I feel ill? Check ketones even if glucose is normal?"
Insulin never on the stop list "How do I adjust my insulin when I am ill?"

KDIGO adds two warnings. There is little evidence that sick-day rules prevent kidney injury, and mistakes happen. The most common problem is forgetting to restart a paused medicine, so the restart plan must be written down (KDIGO 2024, practice points 4.3.2–4.3.3). A medicine review within a month after the illness helps catch anything not restarted (KDIGO 2024).

Food and fluids when you are ill

If you cannot eat normal meals, these are kinder to a kidney diet than orange juice or milk. Values are per serving from USDA FoodData Central, as in the app's food list (USDA):

Food or drink Carbohydrate Potassium Fluid
Cranberry juice cocktail, ½ cup 17 g 18 mg 120 mL
Apple juice, ½ cup 14 g 125 mg 120 mL
Ginger ale or lemon-lime soda, regular, 4 oz 11–13 g 1 mg 120 mL
Gelatin dessert, regular, ½ cup 19 g 1 mg 120 mL (counts as fluid)
Ice pop, 1 (1¾ fl oz) 10 g 8 mg about 50 mL
Applesauce, unsweetened, ½ cup 14 g 90 mg small
Saltine crackers, 5 11 g 23 mg none (141 mg sodium)
White bread or toast, 1 slice 14 g 37 mg none (142 mg sodium)
Glucose tablets, 4 16 g 0 mg none

Fluid is counted by volume, the cautious way (Fluid). When glucose is high, sugar-free drinks may suit you better; they still count toward a fluid limit. If glucose is low, treat the low first (Treating a low).

On a fluid limit (dialysis, or stage G4–G5 with swelling): general advice says "drink plenty" (CDC), but that does not fit a fluid limit. Losing fluid through vomiting or diarrhea may mean you need more for a day or two; not losing fluid means you do not. Ask your team now for a sick-day fluid allowance and write it on your sick-day card. See Fluid.

On dialysis: do not skip a session because you feel unwell. Call the unit. Missed sessions can make DKA symptoms worse (JBDS 2022).

After a transplant: if you cannot keep your anti-rejection medicines down, call your transplant center the same day, because missed doses risk rejection (KDIGO 2009 transplant, chapter 11). Call them too for a fever over 100 °F (37.8 °C) (NIDDK).

Your sick-day kit

Check it every few months:

  • Blood ketone meter and strips, in date (strips expire)
  • Glucose meter, strips and spare CGM sensor
  • Glucose tablets or gel, and your measured juice or soda
  • Glucagon, in date, and a family member who knows how to use it (Treating a low)
  • Spare pump supplies or pens, and insulin
  • Your written sick-day plan, with restart rules (wallet card)
  • Phone numbers: diabetes team, kidney team, dialysis unit or transplant center, after-hours line
  • Thermometer

Example

Ana has stage G4 kidney disease, takes an ACE inhibitor and has a fluid limit.

  • Day 1, 7 a.m. She wakes up vomiting. Glucose 260 mg/dL (14.4 mmol/L); blood ketones 0.9 mmol/L. She keeps her basal insulin, follows her plan for extra insulin, and pauses her ACE inhibitor because her written plan says to.
  • 9 a.m. Ketones 1.2. She sips small amounts of water within her sick-day fluid allowance and checks again in 2 hours.
  • 11 a.m. Ketones 1.8 and she vomits again. She calls her diabetes team straight away. They tell her to go to the emergency department because she cannot keep fluids down.
  • Day 4. She is well. She restarts the ACE inhibitor on the day her written plan says, books the blood test the plan asks for, and ticks the restart off on her sick-day card.

Ask your care team

  1. Please write my sick-day plan: how to adjust insulin, how often to check, and what to do at each ketone level.
  2. Which of my medicines should I pause when I am vomiting or have diarrhea, and when do I restart each one?
  3. How much extra fluid can I have on a sick day?
  4. Can you prescribe a blood ketone meter and strips?
  5. Who do I call at night or at the weekend?
  6. When should I have a blood test after an illness?

Get help now if…

Call 911 (or your local emergency number) or go to the emergency department

  • Blood ketones 3.0 mmol/L or more, or urine ketones ++ or more (NHS; 2024 consensus).
  • Ketones 1.6 mmol/L or more and you cannot reach your team quickly, or you are vomiting (ADA).
  • Any ketones with vomiting so you cannot keep fluids down (NHS; CDC).
  • You cannot keep liquids down for more than 4 hours, or vomiting or bad diarrhea lasts more than 6 hours (CDC).
  • Glucose stays at 300 mg/dL (16.7 mmol/L) or above, deep or fast breathing, fruity breath, confusion or drowsiness (CDC).
  • A low the person cannot treat themselves: give glucagon and call 911.

See Get help now for every warning sign.

Sources

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