Sick-Day Planning for Diabetes

Illness and diabetes interact in ways that can turn an ordinary flu or stomach bug into a medical emergency. When the body fights infection, stress hormones rise — particularly cortisol and glucagon — which raise blood glucose significantly, even when the person is eating very little or nothing. For adults with Type 1 diabetes, illness substantially increases the risk of diabetic ketoacidosis (DKA). For adults with Type 2 diabetes, illness can cause dangerous hyperglycemia that requires urgent medical attention. A sick-day plan — developed with the care team before illness occurs — prevents these complications by establishing clear rules for what to do when sickness strikes.

The most important principle of sick-day management in diabetes is also the most counterintuitive: do not stop medication because you are not eating. Blood glucose almost always rises during illness, regardless of food intake, because illness stress hormones drive glucose production independently of what you eat. Stopping insulin or oral medication during illness removes the control mechanism at the time it is most needed. This guide covers the complete sick-day protocol — medication rules, monitoring frequency, fluid management, nutrition during illness, and the specific warning signs that require emergency care.

The Core Sick-Day Rules for Adults With Diabetes

Rule 1 — Never Stop Medication During Illness

This rule applies to all adults with diabetes, with two exceptions that require care team guidance. Do not stop insulin because you are not eating — illness stress hormones raise glucose even in the absence of food, and insulin is the control mechanism. Do not stop most oral diabetes medications without specific instruction — metformin, for example, should be temporarily held during severe vomiting or diarrhea (to prevent lactic acidosis from dehydration), but the decision to hold it should come from the care team, not from a general rule about not eating. The exceptions: SGLT-2 inhibitors (empagliflozin, dapagliflozin, canagliflozin) should typically be held during illness because they increase DKA risk in sick-day conditions — specifically during poor fluid intake, vomiting, or reduced carbohydrate consumption. Your care team should have provided sick-day guidance for your specific medication regimen as part of standard diabetes education. If you have never received this guidance, call your care team for sick-day medication instructions before you need them. Our doctor visit checklist for diabetes guide includes sick-day planning as a standard agenda item for diabetes appointments — prompting the care team conversation about medication rules before illness occurs.

Rule 2 — Increase Blood Glucose Monitoring to Every 2–4 Hours

During illness, standard monitoring frequency is insufficient. Glucose can change rapidly during acute illness — from a stress hormone surge, from dehydration concentrating blood glucose, from vomiting preventing carbohydrate absorption, or from an unexpected hypoglycemia episode if appetite is severely suppressed but medication continues unchanged. Check glucose every 2–4 hours around the clock during acute illness. If glucose is above 240 mg/dL (13.3 mmol/L) on two consecutive readings, check ketones. If glucose falls below 70 mg/dL, treat as hypoglycemia per the standard 15-15 protocol. If glucose cannot be stabilized with the existing medication regimen — continuing to rise despite insulin administration — this is a care team call, not a wait-and-see situation. Our blood sugar log and tracking guide covers the monitoring and logging system for capturing the frequent readings that sick-day management requires, and detecting the glucose trend patterns that indicate when escalation is needed.

Rule 3 — Check Ketones if Glucose Is Above 240 mg/dL

Ketones are the warning sign that the body is breaking down fat for fuel at a dangerous rate — the metabolic process that leads to diabetic ketoacidosis (DKA) in insulin-deficient states. During illness, the combination of insulin deficiency (reduced intake, reduced absorption, or inadequate dose for illness-elevated needs) and illness-related stress hormone surges can trigger ketone production rapidly. Test ketones with urine ketone strips or blood ketone meter at any sick-day glucose reading above 240 mg/dL. Trace or small urine ketones (or blood ketones below 0.6 mmol/L) indicate close monitoring and increased fluid intake. Moderate to large urine ketones (or blood ketones above 1.5 mmol/L) indicate a call to the care team or emergency line immediately. The specific ketone thresholds for your situation — particularly for adults with Type 1 diabetes — should be established with your care team as part of sick-day planning before illness. Waiting to check ketones until symptoms of DKA appear (nausea, vomiting, abdominal pain, fruity breath, confusion) means the DKA process has already advanced significantly and emergency care is required.

Rule 4 — Maintain Fluid Intake Even Without Appetite

Dehydration worsens hyperglycemia — concentrated blood volume means higher glucose concentration per unit of blood. During illness with reduced appetite, fluid intake must replace both normal daily needs and illness-related fluid losses (fever, sweating, vomiting, diarrhea). Target at least 8 ounces (240 mL) of clear fluid per hour while awake during illness. If glucose is high, choose sugar-free fluids — water, diet electrolyte drinks, broth. If glucose is low or you are not eating at all, choose fluids with glucose content — regular juice, regular sports drinks — in small amounts (4 ounces per hour). If vomiting prevents fluid retention and you cannot keep 4 ounces of fluid down for 2 consecutive hours, this is a care team or emergency call — significant dehydration in a person with diabetes is a medical emergency that typically requires intravenous fluids.

Nutrition During Illness — Eating When You Don’t Want To

Carbohydrate Targets for Sick Days

When appetite is suppressed but glucose is not dangerously low, aim for 45–50 grams of carbohydrate every 3–4 hours to maintain fuel availability and prevent starvation ketosis. This is not a meal — it is a medicinal carbohydrate intake. Foods that are easily tolerated during illness and provide approximately 15 grams of carbohydrate include: 4 ounces of juice, 6 regular crackers, 1 small banana, 1 cup of broth with noodles, or 1/2 cup of regular (non-diet) gelatin. If glucose is elevated and appetite is absent, maintain fluid intake without carbohydrate — the insulin or medication should be managing the stress-hormone-driven glucose elevation. If glucose is normal or low and appetite is absent, the 15-gram carbohydrate-per-hour approach prevents glucose from dropping dangerously while medication continues.

When You Cannot Keep Food or Fluid Down

Persistent vomiting — more than 2–3 episodes per hour for 2 hours — in an adult with diabetes requires a call to the care team or emergency services. This is not a situation to manage at home without guidance. The combination of inability to retain fluid, continuing medication (particularly insulin), and illness-driven stress hormone glucose elevation creates rapid physiological deterioration. Intravenous fluid and glucose management in a clinical setting is the appropriate intervention. Do not continue to attempt home management of diabetes during persistent vomiting without medical guidance. The physiological stress that illness places on glucose control — and the family support role in recognizing when emergency escalation is needed — is covered in our family support for diabetes management guide.

When to Call Your Doctor or Go to Emergency Services

Call the Care Team When

• Glucose above 240 mg/dL on two consecutive readings despite medication
• Moderate or large ketones on urine test, or blood ketones above 1.5 mmol/L
• Unable to keep fluids down for 2+ consecutive hours
• Illness lasting more than 24 hours without improvement
• Fever above 101°F (38.3°C) lasting more than 24 hours
• Signs of infection — wound not healing, spreading redness, increased discharge
• Uncertainty about how to adjust medication during illness

Go to Emergency Services Immediately When

• Confusion, difficulty speaking, or extreme drowsiness
• Fruity or acetone breath (sign of advanced DKA)
• Rapid breathing, shortness of breath at rest
• Chest pain
• Glucose above 500 mg/dL (27.8 mmol/L) or glucometer showing “HI”
• Glucose below 50 mg/dL that does not respond to two rounds of 15-gram glucose treatment
• Loss of consciousness

Having this emergency call information written down and accessible — before illness occurs — is a core component of sick-day planning. When severely unwell, it is not the time to search for contact numbers or recall thresholds. The sick-day plan should be a physical document stored with the sick-day kit, reviewed with the care team, and shared with household members. Our annual diabetes care checklist includes sick-day plan review as a standard annual item — ensuring the plan remains current with current medications and care team contact information. The building healthy habits guide that covers the habit maintenance approach during illness — preserving medication and monitoring while suspending other self-care habits — is in our building healthy habits with diabetes guide. The traveling with diabetes guide that applies sick-day principles to illness occurring away from home — when the home care team is unavailable and familiar pharmacies are absent — is in our traveling with diabetes guide. The emotional health guide covering the anxiety and distress that acute illness episodes can trigger in adults who are already managing diabetes-related psychological burden is in our emotional health and diabetes management guide. The diabetes burnout guide covering recovery from the self-care collapse that extended illness can trigger — when a period of medically justified self-care suspension becomes a longer-term disengagement — is in our diabetes burnout guide. The family support guide covering how family members can provide appropriate, safe sick-day support — including when to call emergency services on behalf of a family member who is too unwell to make that decision — is in our family support for diabetes management guide. The ADA’s sick-day management guidance covers illness rules for insulin-dependent and non-insulin-dependent adults with diabetes, including DKA prevention and the specific decision points for emergency escalation. The NIDDK’s diabetes management overview integrates sick-day planning within the comprehensive diabetes care framework. The CDC’s living with diabetes resources cover illness management and sick-day planning across Type 1 and Type 2 diabetes in their comprehensive diabetes self-management education content.

Assembling Your Sick-Day Kit — Before Illness Strikes

Why the Kit Must Exist Before You Need It

Illness arrives without warning. When you have a fever of 103°F and feel too weak to stand, finding ketone strips or locating the care team’s emergency number requires effort that is genuinely difficult in that state. The sick-day kit — assembled during health, when thinking clearly — removes the search burden from the moment it is most costly. Every adult with diabetes should have this kit prepared, accessible, and reviewed with household members who can help implement it during illness.

What Goes in the Sick-Day Kit

The sick-day kit is a dedicated box, bag, or drawer containing all illness-specific supplies. Stock it with:

• Urine ketone strips (or blood ketone meter if available) — stored unexpired
• Extra glucose test strips beyond daily supply
• Thermometer — fever tracking is part of sick-day monitoring
• Glucose tablets — at least 3 tubes
• Regular (non-diet) juice boxes — 4-ounce boxes for glucose correction
• Clear broth (low-sodium if possible) — for illness fluid and electrolyte intake
• Written sick-day plan — including glucose thresholds, ketone thresholds, and emergency contact information
• Care team emergency or after-hours phone number
• List of all current medications with doses
• Glucagon emergency kit or nasal glucagon

Review the kit annually. Replace expired strips and medications. Confirm the care team contact number is current. Share the kit location and basic sick-day plan with household members. Our annual diabetes care checklist includes sick-day kit review as a standard annual preparation task alongside clinical appointments and laboratory testing.

Sick-Day Management for Type 1 Diabetes — Special Considerations

DKA Risk Is Higher and More Rapid in Type 1

Adults with Type 1 diabetes face a substantially higher risk of diabetic ketoacidosis during illness than those with Type 2. In Type 1, the complete absence of endogenous insulin means that any reduction in insulin delivery — from missed doses, degraded insulin, or absorption changes — immediately triggers ketone production. Illness stress hormones simultaneously increase glucose and reduce insulin sensitivity, increasing the insulin need precisely when absorption and delivery are often most disrupted. Adults with Type 1 diabetes should begin checking ketones at any sick-day glucose above 240 mg/dL (or as directed by their care team — some teams recommend starting ketone checks at 200 mg/dL during illness). The timeline from early ketone elevation to severe DKA is measured in hours in some cases — not days. This rapidity means that the conservative rule of calling the care team at moderate ketones is especially important for Type 1 adults. Do not wait for DKA symptoms to develop before making the call.

Insulin Dose Adjustment During Type 1 Illness

Many adults with Type 1 diabetes follow a correction dose formula for sick-day insulin management — increasing basal rates on insulin pumps, or adding correction doses of rapid-acting insulin every 4 hours based on the glucose reading, beyond the standard correction scale used on well days. These illness-specific correction formulas should be provided by the care team as part of standard Type 1 sick-day planning. If you have Type 1 diabetes and have never been given a written sick-day insulin adjustment plan, request this at your next appointment — it is a standard component of Type 1 diabetes education that significantly reduces DKA hospitalization risk. The overall blood glucose management framework for adults with Type 1 diabetes — including the exercise considerations that intersect with sick-day management during recovery from illness — is in our safe exercise with diabetes guide.

Sick Days During Specific Illness Types

Gastrointestinal Illness — Vomiting and Diarrhea

Gastrointestinal illness creates the most complex sick-day management challenge because it simultaneously prevents normal food and fluid intake (removing the carbohydrate that insulin is dosed to cover), causes significant fluid and electrolyte loss, and triggers the illness stress hormone response that raises glucose. The specific complication: taking a rapid-acting insulin dose that was calibrated to a standard meal, then vomiting before the meal is absorbed, can produce severe hypoglycemia with the meal’s glucose contribution absent and the insulin fully active. During gastrointestinal illness, do not administer meal insulin until food is retained for at least 15 minutes. Focus on clear fluid intake to prevent dehydration. Check glucose every 2 hours. If glucose is falling and you cannot retain carbohydrate sources to prevent hypoglycemia, call the care team immediately — this is not a situation to manage without guidance. The hydration principles for diabetes management — relevant for both sick-day and standard-day fluid management — are covered in our blood sugar log and tracking guide.

Respiratory Illness — Fever and Glucose Management

Respiratory illness — colds, flu, COVID-19, respiratory infections — produces sustained fever that significantly elevates glucose through cortisol and glucagon stress hormone release. For each degree Fahrenheit of fever, insulin sensitivity typically decreases, meaning more insulin is needed to achieve the same glucose control. Adults with Type 1 diabetes typically need 10–20% more insulin during febrile respiratory illness. Adults with Type 2 on insulin may need similar adjustments. Adults with Type 2 on oral medications may see glucose rise significantly despite medication — requiring care team guidance on whether additional medication or temporary insulin is appropriate. The stress eating and blood sugar guide — which covers the cortisol mechanism that also operates during illness stress — is in our stress eating and blood sugar guide. The sleep disruption that respiratory illness produces — and its independent effect on glucose regulation through insulin sensitivity pathways — is in our poor sleep and blood sugar spikes guide. The emotional health guide covering the anxiety and overwhelm that acute illness can trigger in adults already managing diabetes-related psychological burden — including how to maintain emotional stability during physically stressful illness periods — is in our emotional health and diabetes management guide. The building healthy habits guide covering the minimum viable habit approach during illness — what to maintain and what to temporarily suspend — is in our building healthy habits with diabetes guide. The diabetes burnout guide covering the recovery from self-care collapse that extended illness sometimes triggers — when medically justified suspension of self-care becomes longer-term disengagement — is in our diabetes burnout guide. The traveling with diabetes guide that applies sick-day principles to illness occurring away from home — when home care infrastructure is unavailable — is in our traveling with diabetes guide.

Sick-Day Plan — Written Protocol Template

What the Written Plan Should Include

A written sick-day plan removes the requirement to make clinical decisions when feeling too unwell to think clearly. The plan should be specific to your medication regimen and established with your care team. It should include the following components:

Glucose monitoring schedule: “During illness, check glucose every 2 hours while awake. Check at 3 a.m. if glucose was above 200 mg/dL at bedtime.”

Ketone testing threshold: “Check ketones whenever glucose is above [your threshold, typically 240 mg/dL or as specified by your care team].”

Medication instructions: “Take [all regular medications] as usual unless vomiting prevents it. Do not stop insulin. Hold [SGLT-2 inhibitor name] during illness. Call the care team if [specific glucose or ketone threshold is reached].”

Fluid intake target: “Drink at least 8 oz of fluid every hour while awake. If glucose is above 200 mg/dL, use sugar-free fluids. If glucose is below 100 mg/dL, use regular juice or sports drink.”

Carbohydrate intake target: “If not eating normal meals, consume 45 grams of carbohydrate every 3–4 hours while glucose is in the normal range. Examples: [your specific list of tolerable illness foods with carbohydrate content].”

Escalation thresholds — call care team: “Call [care team number] if: glucose above [threshold] on two checks; ketones moderate or large; unable to keep fluids down for 2 hours; fever above 101°F for more than 24 hours; symptoms worsening after 24 hours.”

Emergency escalation — call 999/112/911: “Go to emergency immediately if: confusion or difficulty speaking; fruity breath; glucose above 500 mg/dL; rapid breathing at rest; glucose below 50 mg/dL not responding to two rounds of treatment; loss of consciousness.”

This written plan should be reviewed and updated at each annual diabetes review. The document should be stored with the sick-day kit and a copy kept accessible on a smartphone. Share it with household members so they can implement it on your behalf if you become too unwell to manage independently. Our doctor visit checklist for diabetes guide includes sick-day plan creation as a core agenda item — ensuring the specific thresholds and instructions are established collaboratively with the care team rather than estimated independently. The family support role in sick-day management — including how household members can implement the sick-day plan, recognize escalation triggers, and know when to call emergency services — is in our family support for diabetes management guide. The annual care review that maintains this plan current — with correct medications, current care team contacts, and updated thresholds based on changing clinical situation — is in our annual diabetes care checklist.

Sources: American Diabetes Association Standards of Care in Diabetes 2024; American Diabetes Association Sick Day Management Guidelines 2024; NIDDK Diabetes and Sick Days 2024; CDC Living With Diabetes 2024; Kitabchi AE et al. Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar State. Diabetes Care 2009.