What Should I Do When I’m Sick and Can’t Eat?
This article is for education and does not replace medical advice. Follow your care team’s instructions and your personal sick-day plan. Get emergency help right away for serious symptoms.
When you’re sick and unable to eat, you may wonder how to manage your diabetes.
There are practical things you can do at home, and we’ll walk through them below. But your first step is to call your doctor or diabetes care team.
Let them know how you’re feeling and ask what to do, including how to manage nausea, vomiting, or diarrhea and when to go to the ER.
If you have emergency warning signs, get help right away rather than waiting for a return call.
You do not have to figure everything out at once. Start with that call, follow your sick-day plan, and ask someone you trust to help if needed.
1. Why Is My Blood Sugar High When I’m Unable to Eat?
“I haven’t eaten. Why is my blood sugar going up?”
Food is only one thing that affects blood sugar. When you are sick, your body releases stress hormones to help fight the illness. These hormones can cause your liver to release stored sugar into your blood. Your body may also need more insulin than usual.
That means your blood sugar can rise even when you are eating very little. A high reading does not mean you did something wrong. It means your body needs closer attention while it is dealing with illness.
Blood sugar can also drop when you cannot eat or keep food down, especially with certain diabetes medicines. This is why checking your readings matters more than guessing how they should look.
2. What Can I Do About Nausea, Vomiting, or Diarrhea?
Tell your care team when your symptoms began, how often they are happening, and whether you can keep drinks down.
Ask what treatment is safe for you.
Before taking an over-the-counter medicine, check with your doctor or pharmacist. Some products may affect your blood sugar, blood pressure, or other medicines.
Vomiting and diarrhea can cause you to lose water and important salts. Watch for a dry mouth, darker urine, less urination, or dizziness when standing. These can be signs of dehydration—when your body loses more fluid than it takes in.
Start slowly with fluids. As a nurse, I encourage starting with a small sip every five minutes until you have finished a 4-ounce glass (check with your doctor first).
If those sips stay down, gradually increase the amount you drink each time, while keeping the five-minute interval. Avoid drinking a large amount at once.
If you have a prescribed fluid limit, follow your care team’s guidance.
If vomiting continues and your doctor has prescribed medicine for nausea, take it exactly as directed. If it does not help and you still cannot keep fluids down, go to the ER.
Do not wait for the medicine to work if you have emergency warning signs, such as trouble breathing, confusion, fainting, or high ketones.
If fluid losses continue, ask whether you need an oral rehydration solution.
This replaces water and salts; it is different from many sports drinks. A store-brand product may be an affordable choice.
Mix it exactly as directed.
3. What Can I Eat or Drink?
You do not need an expensive “diabetic” drink or supplement to begin caring for yourself.
If you can eat, try small portions more often. Simple choices may include soup, crackers, cooked cereal, or unsweetened applesauce.
Choose what you can tolerate and follow the food guidance in your sick-day plan.
Water and other sugar-free drinks can help with fluids. But if you cannot eat your usual meals, you may also need foods or drinks that contain carbohydrates.
Your care team can help you decide how much based on your readings, medicines, and usual needs.
Treat a low blood sugar promptly.
For most adults, a reading below 70 mg/dL is low.
If you are awake and can swallow safely, take 15 grams of fast-acting carbohydrate, such as:
½ cup of juice or regular soda.
Glucose tablets totaling 15 grams, according to the label.
Wait 15 minutes and check again. If it is still below 70, repeat.
Once the low is corrected, have a snack or meal containing carbohydrate and protein as tolerated. Follow any different instructions in your personal plan.
Diet soda and sugar substitutes will not treat a low. If you cannot keep the treatment down, get emergency help.
If you have a prescribed fluid limit because of heart or kidney disease, ask your care team how to manage fluids during this illness.
4. What Should I Monitor and Write Down?
Start a written record as soon as you feel sick. A notebook or a note on your phone is enough.
Begin with the date and approximate time your symptoms started. Doctors often ask, “When did this begin?” If you are unsure, write your best estimate.
Then record:
Blood sugar readings, with the date and time.
Blood-pressure readings when appropriate, with the date and time.
Symptoms and changes, including how often vomiting or diarrhea occurs.
What you eat and drink, roughly how much, and whether it stays down.
Each medicine taken, including its name, dose, and time.
Your temperature if you have a thermometer.
Blood sugar often needs checking at least every four hours during illness, including overnight when directed.
Your care team may recommend more frequent checks.
Ask when to check ketones (in urine), acids that can build up when your body does not have enough insulin. This is especially important with type 1 diabetes, but some people with type 2 need ketone testing too.
Illness, blood sugar of 250 mg/dL or above, or symptoms of ketoacidosis are reasons to check and follow your care team’s instructions.
If you have high blood pressure or take blood-pressure medicine, ask how often to monitor it. Keep a record and share it with your care team.
Have your notes ready during phone calls and take them to an appointment or the ER.
Trying to remember everything when you already feel sick can add stress. A simple written record gives you one less thing to worry about.
5. What About My Medicines?
Ask your doctor or diabetes care team to help you make a written sick-day plan before you become ill.
It should explain any medicine changes, what to monitor, and when to call for help.
Having a plan helps you take the right steps sooner and can put you on a faster path to feeling better. You’ll be prepared instead of trying to figure everything out when you are not feeling your best.
Different medicines need different instructions. Some may need to be paused during vomiting, diarrhea, or dehydration. Others must continue, sometimes with a dose change.
Your plan should name the medicines and explain when to restart anything that is paused.
For example, metformin may need to be held during a dehydrating illness.
Insulin instructions are different: people with type 1 diabetes must not stop their background insulin, even when they cannot eat.
Get guidance about dose changes.
Medicines called SGLT2 inhibitors, such as Jardiance or Farxiga, need special sick-day precautions.
They can cause ketoacidosis even when blood sugar is not very high.
If you take one and develop nausea, vomiting, stomach pain, unusual tiredness, or trouble breathing, stop that medicine and seek medical attention immediately.
Also, avoid “chasing numbers” with extra doses. Some insulins keep working for many hours.
Follow your prescribed correction plan rather than adding doses too soon.
Do not take extra blood-pressure medicine to correct a single reading unless your care team has specifically instructed you to do so.
Ask about changes rather than guessing.
6. When Should I Call Again or Go to the ER?
Contact your care team promptly if symptoms are worsening, readings keep falling outside your plan’s limits, or you are unsure how to manage food, fluids, or medicines.
Report signs of dehydration, such as passing much less urine or dizziness that continues when you stand.
Get emergency care right away if:
You have trouble breathing, new confusion, fainting, or difficulty staying awake.
Your blood sugar stays at 300 mg/dL or above.
You have high ketones or signs of ketoacidosis, such as vomiting with stomach pain, fruity breath, or deep, rapid breathing.
You are vomiting and cannot keep fluids down.
The CDC also advises going to the ER if you cannot keep liquids down for more than four hours, have vomiting or severe diarrhea for more than six hours, or cannot keep food down for more than 24 hours.
These are not instructions to wait. Seek help sooner if you are getting worse or your plan says to.
Call 911 for a severe low if the person is unconscious, having a seizure, or unable to swallow safely.
Give prescribed glucagon if available and you know how.
Do not give food or drink to someone who cannot swallow safely. Get emergency help if a low cannot be corrected or sugar cannot be kept down.
Do not drive yourself if you are confused, faint, or having low blood sugar. Have someone help you.
Take your medicine list and notes if they are handy but never delay emergency care to gather them.
7. What Should I Keep in a Sick-Day Kit?
Gather supplies a little at a time, using what you already have when possible:
Your written sick-day plan.
Care-team and after-hours phone numbers.
A current medicine list.
Your glucose meter, strips, lancets, and needed CGM or pump supplies.
Ketone testing supplies if recommended.
Fast-acting sugar and prescribed glucagon, if applicable.
A thermometer.
Suitable drinks and easy-to-prepare foods.
A notebook and pen.
Check expiration dates and let someone you trust know where the kit is kept.
Ask that person to check on you when you are sick. They may be able to bring drinks, write down readings, or make a call when you feel too tired.
Caring for Your Whole Self
I pray that this article helps you heal physically, mentally, and spiritually.
Physically, may you find comfort in God’s presence as you rest and recover.
“God is our refuge and strength, an ever-present help in trouble.” — Psalm 46:1 (NIV)
Mentally, may you find peace in knowing you can ask for help. You don’t have to figure everything out or carry the worry alone.
“I lift up my eyes to the mountains—where does my help come from? My help comes from the LORD, the Maker of heaven and earth.” — Psalm 121:1–2 (NIV)
Spiritually, may you seek God’s wisdom to guide your decisions and give you confidence in your next steps.
“If any of you lacks wisdom, you should ask God, who gives generously to all without finding fault, and it will be given to you.” — James 1:5 (NIV)
Take it one Faithful Step at a time.
🌻 Faithful Steps Tips: A Sick-Day Plan Is for Everyone
You don’t have to have diabetes to benefit from a sick-day plan. Everyone can prepare for illness, especially if you take prescription medicines for blood sugar, heart disease, blood pressure, or another health condition.
Ask your doctor or pharmacist which medicines need special instructions when you cannot eat or drink normally, have vomiting or diarrhea, or become dehydrated. Your written plan should explain what to do, when to call for help, and when to restart any medicine you were told to pause.
Keep the plan with your current medicine list and emergency contact numbers. Share it with someone you trust.
A little preparation now can give you one less thing to worry about when you are not feeling your best.
Real Faith • Real Health • Real Life
Sources and Research for Yourself
Learning about sick-day care can help you feel more prepared. These trusted resources were used to develop this article. Use them to learn more and discuss a personal sick-day plan with your doctor or diabetes care team.
General advice may differ between sources because people use different medicines and have different health needs. Ask your care team which instructions apply to you.
The small-sip schedule described in this article is my practical nursing approach. The resources below support starting with small sips and increasing gradually as tolerated; they do not prescribe that exact five-minute schedule.
Diabetes and Sick-Day Planning
American Diabetes Association — Planning for Sick DaysIllness, blood sugar, ketones, written plans, and sick-day supplies.https://diabetes.org/living-with-diabetes/sick-days
CDC — Managing Sick DaysMonitoring, food and drinks, and when to seek emergency care.https://www.cdc.gov/diabetes/living-with/managing-sick-days.html
Diabetes UK — Managing Diabetes When You’re UnwellHow illness affects diabetes and why medicine instructions may need to change.https://www.diabetes.org.uk/living-with-diabetes/life-with-diabetes/illness
Low Blood Sugar and Ketones
CDC — Treatment of Low Blood Sugar (Hypoglycemia)The 15-15 rule, fast-acting carbohydrates, and severe low blood sugar.https://www.cdc.gov/diabetes/treatment/treatment-low-blood-sugar-hypoglycemia.html
CDC — Diabetic KetoacidosisKetone testing, warning signs, and emergency treatment.https://www.cdc.gov/diabetes/about/diabetic-ketoacidosis.html
Medicine Safety
CDC — Types of InsulinHow quickly different insulins begin working and how long their effects last.https://www.cdc.gov/diabetes/about/how-to-use-insulin.html
Dorset County Hospital, NHS — Sick Day Rules for People with Type 2 Diabetes Taking an SGLT-2 InhibitorMedicine precautions during illness. Some UK medicine names differ from those used in the United States.https://dchft.nhs.uk/leaflets/sick-day-rules-for-people-with-type-2-diabetes-taking-a-sglt-2-inhibitor/
U.S. Food and Drug Administration — SGLT2 Inhibitor Safety WarningKetoacidosis risk, including when blood sugar is not very high.https://www.fda.gov/media/94822/download
Dehydration and Blood Pressure
NHS — DehydrationSymptoms, fluid replacement, and when urgent help is needed. This UK resource lists UK emergency numbers; in the United States, call 911 for emergencies.https://www.nhs.uk/conditions/dehydration/
American Heart Association — Home Blood Pressure MonitoringChecking blood pressure at home and sharing readings with your care team.https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings/monitoring-your-blood-pressure-at-home
Questions to Take to Your Next Appointment
Which of my medicines should continue, change, or pause when I am sick?
When should I restart a medicine that was paused?
How often should I check blood sugar, blood pressure, or ketones?
What should I eat or drink if I cannot manage a meal?
What should I do if prescribed nausea medicine does not help?
Which readings or symptoms mean I should call you?
When should I go directly to the ER?
Who should I contact after office hours?
Ask for the answers in writing and keep them with your sick-day supplies.
Scripture References
All Bible quotations are from the New International Version (NIV):
Comfort: Psalm 46:1.
Asking for help: Psalm 121:1–2.
Wisdom: James 1:5.
Health resources accessed October 19, 2026.
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