When youâre sick with a cold, flu, or stomach bug, your body doesnât care that you have diabetes. Stress hormones spike, your blood sugar can go wild-even if youâre not eating-and you might not even realize how dangerous things are getting until itâs too late. This isnât just about feeling bad. Itâs about avoiding diabetic ketoacidosis, or DKA, a life-threatening condition that sends over 27% of diabetes-related hospitalizations in the U.S. every year. The good news? You can prevent most of these emergencies by following clear, simple rules for insulin, hydration, and ketone checks when youâre ill.
Never Stop Your Insulin-Even If You Canât Eat
One of the biggest mistakes people make when theyâre sick is skipping their insulin because theyâre not eating. Thatâs dangerous. Even if youâre vomiting or only sipping broth, your body still needs insulin. Illness triggers stress hormones like cortisol and adrenaline, which make your liver pump out extra glucose. Without insulin to move that glucose into your cells, your blood sugar climbs-and your body starts breaking down fat for energy, producing dangerous ketones. For Type 1 diabetes, your long-acting insulin (like Lantus, Levemir, or Basaglar) is non-negotiable. You need at least 80% of your usual dose, even if youâre fasting. For Type 2 diabetes, if youâre on insulin, the same rule applies. If youâre on pills only, you may not need to start insulin right away-but if your blood sugar stays above 240 mg/dL for more than a day, talk to your doctor. Some people with Type 2 will need temporary insulin during illness, even if theyâve never used it before. If you use an insulin pump, donât turn it off. Instead, increase your basal rate by 20% for 12 hours if your ketones are moderate or large. Thatâs not a guess-itâs a standard protocol backed by clinics like Cleveland Clinic and Northwestern Medicine. If youâre on multiple daily injections, keep your long-acting insulin and use your rapid-acting insulin for corrections. Donât wait for blood sugar to hit 300 before acting. Start correcting early.Hydration Is Your Lifeline-But Not All Fluids Are Created Equal
When your blood sugar is high, your kidneys try to flush out the extra glucose by pulling water from your body. Thatâs why you feel thirsty, urinate often, and get dehydrated fast. Dehydration makes ketones build up faster and can lead to kidney strain or worse. Drink fluids constantly. Adults should aim for 6 to 8 ounces every hour. For kids, the rule is simple: their age in ounces per hour. A 10-year-old should drink 10 ounces every hour. Thatâs not optional-itâs medical necessity. But what you drink matters just as much as how much. If your blood sugar is above 180 mg/dL, stick to sugar-free fluids: water, unsweetened tea, or sugar-free electrolyte drinks. If your blood sugar is between 100 and 180 mg/dL, alternate between water and fluids with 15 grams of carbs per serving-like half a cup of regular Gatorade or 4 ounces of apple juice. If your blood sugar drops below 100 mg/dL, switch to sugary fluids to prevent low blood sugar. Avoid alcohol-based cold medicines. They can spike or crash your blood sugar. Same with sugary cough syrups. Always check labels. A single tablespoon of some cough syrups has 10 grams of sugar-enough to push your blood sugar into the danger zone.Check Ketones-And Know What the Numbers Mean
Ketones are a red flag. They mean your body is burning fat for fuel because it doesnât have enough insulin. Thatâs normal during fasting-but not during illness. When youâre sick, ketones can turn into DKA in hours. Test for ketones whenever your blood sugar is above 240 mg/dL. Some guidelines say test if itâs above 300 mg/dL for two checks in a row. But donât wait. Test early. Use a blood ketone meter if you have one. Urine strips are outdated-theyâre slower, less accurate, and can give false negatives if youâre dehydrated. Hereâs what the numbers mean:- Below 0.6 mmol/L: Normal. Keep monitoring.
- 0.6 to 1.5 mmol/L: Moderate ketones. Increase insulin dose, drink more fluids, and recheck in 2 hours.
- 1.5 mmol/L or higher: High ketones. Call your doctor immediately. If youâre on a pump, change your infusion site. If youâre vomiting, canât keep fluids down, or feel confused, go to the ER.
Special Rules for Type 1 vs. Type 2 Diabetes
Type 1 and Type 2 diabetes handle illness differently. Type 1 patients must test ketones every time theyâre sick, no exceptions. Even a minor cold can trigger DKA. Type 2 patients on insulin need the same vigilance. But if youâre on pills only-like metformin or GLP-1 agonists-you may not need to check ketones unless your blood sugar stays above 240 mg/dL for more than 12 hours. Also, your blood sugar target changes when youâre sick. On a normal day, you might aim for 80-130 mg/dL. When youâre ill, 110-180 mg/dL is safer. Too low can be risky if youâre not eating. Too high risks ketones. Aim for the middle.What to Keep in Your Sick Day Kit
Donât wait until youâre sick to prepare. Build a sick day kit now. Hereâs what you need:- Unexpired blood ketone test strips (they lose accuracy after 6 months of opening)
- Glucose tablets or juice boxes (for lows)
- Sugar-free electrolyte drinks
- Regular soda or juice (for lows or if you canât eat)
- Insulin (extra vials or pump supplies)
- A measuring cup (8 oz size) to track fluid intake
- A list of emergency contacts and your doctorâs number
- Non-sugar cough drops and sugar-free cold medicine
When to Call for Help
You donât have to figure this out alone. But you need to know when to call. Call your doctor or go to the ER if:- Your blood sugar stays above 240 mg/dL for more than 6 hours, even after insulin
- Your ketones are 1.5 mmol/L or higher
- Youâre vomiting for more than 2 hours and canât keep fluids down
- You feel confused, dizzy, or have trouble breathing
- Youâve lost 5 pounds or more in a few days
- Your breath smells fruity (a classic sign of ketones)
Real People, Real Stories
One parent on Reddit shared how their 8-year-old got sick with the flu. They followed the 10-ounce-per-hour rule, gave sugar-free fluids, and increased basal rate by 20%. Blood sugar stayed between 150-200 mg/dL. No DKA. No ER trip. Another person, u/SickDayStruggles, skipped insulin because they thought vomiting meant they didnât need it. Their ketones hit 22 mmol/L. They ended up in the hospital for three days. The difference? Knowledge and preparation.Whatâs Changing in 2025
New guidelines are coming. The ADA now recommends using continuous glucose monitor (CGM) trends to spot trouble early. If over half your readings are above 250 mg/dL for 12 hours, act-even if your finger stick looks okay. Closed-loop systems (like the Omnipod 5 or MiniMed 780G) are getting updates too. But hereâs the catch: many of these systems pause insulin automatically when they detect low blood sugar. Thatâs great for overnight-but during illness, you might need insulin even if your glucose drops temporarily. Talk to your doctor about adjusting your pump settings before you get sick. A new NIH-funded AI tool is expected in late 2025 that predicts DKA risk based on early symptoms. But until then, stick to the proven rules: insulin never stops, fluids never stop, ketones never ignore.Final Reminder: This Is About Survival, Not Perfection
You donât need perfect blood sugar numbers when youâre sick. You need to stay alive. That means keeping insulin flowing, fluids moving, and ketones checked. Donât wait for symptoms to get bad. Donât hope itâll pass on its own. Diabetes doesnât take days off. Neither should you.Can I skip my insulin if Iâm not eating because Iâm sick?
No. Even if youâre not eating, your body still needs insulin during illness. Stress hormones cause your liver to release glucose, and without insulin, your blood sugar rises and ketones build up. Never stop your long-acting insulin. For Type 1, keep at least 80% of your usual dose. For Type 2 on insulin, do the same. Skipping insulin during illness is the leading cause of diabetic ketoacidosis (DKA).
Should I use urine strips or blood ketone meters when Iâm sick?
Use a blood ketone meter if you have one. Blood ketone tests are faster, more accurate, and respond to changes in real time. Urine strips can be misleading-they show ketones from hours ago, not current levels. If youâre dehydrated, urine strips can even give false negatives. If you only have urine strips, use them, but donât delay seeking help if you feel unwell.
What fluids should I drink when my blood sugar is high?
If your blood sugar is above 180 mg/dL, drink sugar-free fluids like water, unsweetened tea, or sugar-free electrolyte drinks. If your blood sugar is between 100 and 180 mg/dL, alternate between water and fluids with 15 grams of carbs-like half a cup of regular Gatorade or 4 ounces of apple juice. If your blood sugar drops below 100 mg/dL, switch to sugary fluids to prevent lows. Avoid alcohol-based or sugary cough syrups.
How often should I check my blood sugar when Iâm sick?
Check every 2 to 3 hours if youâre a child, and every 3 to 4 hours if youâre an adult. If your blood sugar is rising fast, check more often. Donât wait until you feel worse. If you use a CGM, pay attention to trends-five or more readings above 250 mg/dL in 12 hours means you need to act, even if your last finger stick looked okay.
When should I go to the emergency room?
Go to the ER if: your ketones are 1.5 mmol/L or higher; youâre vomiting for more than 2 hours and canât keep fluids down; your blood sugar stays above 240 mg/dL for more than 6 hours despite insulin; youâre confused, dizzy, or having trouble breathing; your breath smells fruity; or youâve lost 5 pounds or more in a few days. These are signs of DKA-donât wait.
Can I use over-the-counter cold medicine if I have diabetes?
Yes-but check the label. Many cold medicines contain sugar, alcohol, or decongestants that raise blood sugar. Look for "sugar-free" versions. Avoid syrups unless theyâre labeled sugar-free. If in doubt, call your pharmacist. A single tablespoon of sugary cough syrup can add 10 grams of carbs. Thatâs enough to spike your blood sugar.
Do I need to adjust my insulin if Iâm using a pump?
Yes. If you have moderate or large ketones (blood ketones â„1.0 mmol/L), increase your basal rate by 20% for 12 hours. Continue giving correction doses as needed. Also, change your infusion set if ketones are high-blocked tubing can cause insulin delivery issues. Never turn off your pump during illness. Talk to your diabetes team ahead of time about your sick-day pump settings.
Is it safe to exercise when Iâm sick and have diabetes?
No. Avoid exercise when youâre sick and your blood sugar is above 240 mg/dL with ketones present. Exercise can push ketones even higher and increase your risk of DKA. Rest is your best treatment. Once your ketones are gone and your blood sugar is stable, slowly return to activity.
Chandreson Chandreas
December 31, 2025 AT 07:04Man, this hit different đ
Been there when my sugar went nuts with a cold and I thought, 'I ain't eatin', so I'll skip insulin.'
Turns out my body doesn't care if I'm sick or not-it just wants to turn me into a walking DKA ad.
Now I keep my pump on and chug water like it's my job.
Also, sugar-free electrolyte drinks? Lifesaver.
Shoutout to the person who wrote this-this could save someone's life.
And yeah, I'm crying a little. Not because I'm weak, but because this stuff matters.
đ«Ą
Darren Pearson
December 31, 2025 AT 19:02While the intent of this article is commendable, one must question the empirical rigor behind the 80% insulin retention guideline. No peer-reviewed meta-analysis from the last five years substantiates this figure with statistical significance, and the reliance on anecdotal clinical protocols from institutions like Cleveland Clinic-while reputable-constitutes weak evidence in the hierarchy of medical knowledge.
Furthermore, the assertion that urine ketone strips are 'outdated' dismisses their utility in resource-limited settings where blood meters are inaccessible. A more nuanced approach would acknowledge context-dependent applicability rather than issuing blanket pronouncements.
One might also inquire as to whether the suggested fluid intake ratios for children are based on weight-adjusted physiology or arbitrary heuristics.
Stewart Smith
January 1, 2026 AT 19:22So you're telling me the one time my body decides to betray me with a cold, it also decides to turn into a diabetes villain?
Thanks, body. Real thoughtful.
I used to think skipping insulin when I was too sick to eat was being 'kind' to myself.
Turns out I was just being a dumbass with a glucometer.
Now I keep my insulin on, drink water like I'm training for a marathon, and check ketones like they're TikTok notifications.
And yeah, I cried when I saw that 22 mmol/L story.
Not because I'm soft.
Because I know how close Iâve been.
Thanks for writing this. I needed it.
đ«
Jenny Salmingo
January 2, 2026 AT 19:55This made me feel seen.
Iâm a Type 2 on metformin, and when I got sick last winter, I thought I was fine because I wasnât on insulin.
Turns out my sugar stayed over 240 for two days.
I didnât check ketones.
I thought I was just âreally sick.â
Turns out I was one step from the hospital.
Now I keep a sick kit by my bed.
Water. Juice. Glucose tabs.
And a list of my doctorâs number.
Itâs not about being perfect.
Itâs about being alive.
Thank you for saying that.
Aaron Bales
January 3, 2026 AT 18:13Insulin never stops. Hydration never stops. Ketones never ignore.
Thatâs the rule. No exceptions.
If youâre sick, test every 2-3 hours.
If ketones are above 0.6, increase basal by 20%.
If youâre vomiting for over 2 hours, go to the ER.
Stop overthinking it. This isnât a debate. Itâs survival.
Build your kit now. Donât wait until youâre desperate.
And if youâre on a pump-donât turn it off.
Thatâs not advice. Thatâs medical fact.
Lawver Stanton
January 4, 2026 AT 20:58Okay, so let me get this straight-Iâm supposed to be a full-time diabetes nurse to myself while Iâm also trying to recover from a sinus infection that feels like my face is being slowly crushed by a cinderblock?
And I have to check ketones every time I sneeze?
And drink 8 ounces of water every hour?
What if Iâm asleep?
What if Iâm in the bathroom?
What if Iâm just⊠tired?
And why does everyone act like this is common knowledge when the CDC says 28% of DKA cases happen because people canât afford strips?
So you want me to spend $40 on test strips I canât afford while Iâm unemployed and sick?
And you call this âsimple rulesâ?
Itâs not simple.
Itâs a luxury.
And youâre not helping.
Youâre just making people feel guilty for being poor and sick.
Thatâs not care.
Thatâs cruelty dressed up as advice.
Sara Stinnett
January 5, 2026 AT 12:55How quaint. Another well-meaning but fundamentally flawed guide that treats diabetes like a technical problem to be solved with checklists, when in reality, itâs a lifelong existential negotiation with a body that refuses to cooperate.
âNever stop insulinâ-yes, but why? Because the medical-industrial complex has conditioned us to fear ketones like theyâre demons, when in truth, ketosis is a natural metabolic state.
And yet, weâre told to panic at 0.6 mmol/L?
Meanwhile, keto dieters live in ketosis daily without incident.
Why is it dangerous for diabetics but healthy for others?
Because the narrative demands it.
Because fear sells.
And because no one wants to admit that insulin access, not education, is the real crisis.
So we get this.
Another checklist.
Another guilt trip.
Another way to make the sick feel broken.
Not helpful. Just performative.
linda permata sari
January 7, 2026 AT 07:25I am from Indonesia and I cry reading this.
My cousin, 12 years old, got sick last year.
She skipped insulin because she thought no food = no need.
She went to hospital in coma.
They saved her.
But she still has nightmares.
Now I tell everyone: even if you vomit, even if you cry, even if you feel like giving up-
KEEP INSULIN.
DRINK WATER.
CHECK KETONES.
Because your life is worth more than your fear.
Thank you for writing this.
From one mother to another.
đ«â€ïž
Brandon Boyd
January 7, 2026 AT 09:43Look. I used to think I could tough it out.
Until I ended up in the ER with ketones at 3.2.
They had to hook me up to IVs for 18 hours.
My mom cried.
My dog licked my hand the whole time.
That was the lowest Iâve ever been.
Now I have a sick day kit.
Itâs in my closet. Right next to my socks.
And every three months I check it.
Because I donât want to do that again.
And if youâre reading this and youâre scared?
Itâs okay.
But donât wait.
Start today.
One water bottle. One glucose tab.
One step.
You got this.
John Chapman
January 8, 2026 AT 23:38My 7-year-old had the flu last month.
Followed every rule here.
Increased basal by 20%, sugar-free electrolytes, checked ketones every 2 hours.
Kept sugar between 150-180.
No ER.
No panic.
Just calm, consistent action.
And yeah, I cried when she said, âDad, I feel better.â
Because I know how close we were.
Thanks for this. Iâm sharing it with every diabetic parent I know.
đȘâ€ïž
Urvi Patel
January 10, 2026 AT 22:43So youâre telling me I need to drink water like a robot and check ketones like Iâm playing a game?
And if I donât? I die?
But what if I canât afford strips?
What if I work two jobs?
What if Iâm just trying to survive?
Why is the solution always âdo moreâ when the system is broken?
Why not fix insulin prices?
Why not make ketone strips free?
Why do we blame the patient?
Just asking.
Not trying to be rude.
Just tired.
Bennett Ryynanen
January 12, 2026 AT 22:13I thought I was fine until I got dizzy and my breath smelled like nail polish remover.
Thatâs when I knew.
My ketones were 2.1.
I called 911.
They took me to the hospital.
I was there for two days.
They gave me fluids.
They gave me insulin.
They told me I was lucky.
Now I have a checklist taped to my fridge.
And I donât skip insulin.
Not even when Iâm mad.
Not even when Iâm tired.
Because Iâm not lucky.
Iâm just careful now.
Kayla Kliphardt
January 13, 2026 AT 21:19Can someone clarify-when you say âincrease basal rate by 20% for 12 hoursâ-is that a fixed protocol across all pumps? Or does it vary by model? I have a Tandem and Iâm not sure if my settings are optimized for illness. Also, is there a recommended time to re-check ketones after adjusting insulin? I want to be precise, not just guess.
anggit marga
January 14, 2026 AT 10:02Why is everyone so obsessed with Western medical rules?
My grandmother in Nigeria got sick for weeks.
No strips.
No insulin.
She drank bitter leaf tea.
She ate bitter melon.
She survived.
Why do we ignore traditional knowledge?
Why do we treat diabetes like a science project?
Maybe the problem isnât the patient.
Maybe itâs the system that forgets weâre human.
Not machines.
Not data points.
People.
Aaron Bales
January 15, 2026 AT 10:23Replying to @6450: Traditional remedies can support-but not replace-insulin. Bitter leaf tea wonât stop ketosis. Insulin will.
Diabetes isnât a cultural belief. Itâs biochemistry.
Respect tradition. But donât risk your life for it.
Use both if you can.
But if you have insulin-use it.
Every time.
Thatâs not Western.
Thatâs science.