Any physical illness, from a common cold to a gastrointestinal infection, places significant stress on the body, which can disrupt diabetes management. The body’s natural response to sickness involves releasing stress hormones like cortisol and adrenaline to fight the infection. These hormones counteract the effects of insulin, causing the liver to release more stored glucose and leading to a rapid and unpredictable rise in blood sugar levels, even if a person is not eating. Having a pre-established “sick day plan” is important for preventing severe, life-threatening complications such as Diabetic Ketoacidosis (DKA) or Hyperosmolar Hyperglycemic State (HHS). Following specific protocols for testing, hydration, and medication adjustments can help safely navigate an illness without requiring emergency intervention.
Essential Monitoring and Testing Protocols
When an illness begins, the frequency of monitoring blood glucose (BG) must increase significantly beyond the usual schedule. While a person is sick, blood sugar should be checked at least every two to four hours, and this heightened monitoring should continue throughout the night. Recording these results, along with any insulin doses given or food consumed, helps the healthcare team determine if the management plan needs adjustment.
A particularly important step for individuals with type 1 diabetes, and sometimes type 2, is testing for ketones. Ketones are acidic byproducts produced when the body breaks down fat for energy because it cannot use glucose due to an insulin shortage. This fat breakdown happens more readily during illness, and a buildup of ketones can quickly lead to DKA, a serious medical condition.
Ketone testing should be performed whenever blood glucose levels are elevated, typically above 250 mg/dL, or if symptoms like nausea, vomiting, or abdominal pain are present, regardless of the BG reading. Blood ketone meters provide the most accurate and immediate results, showing a precise level of ketones in the bloodstream. Urine ketone strips are an alternative, offering a qualitative result (small, moderate, or large) that indicates the presence of ketones.
If a test shows moderate or large levels of ketones, or if blood ketone levels exceed a threshold like 1.5 mmol/L, it signals a need for immediate action. This usually involves supplemental insulin and increased fluid intake. Continued, frequent testing is necessary until the ketone levels return to an acceptable range.
Maintaining Hydration and Calorie Intake
Illness often suppresses appetite and can lead to vomiting or diarrhea, making it difficult to maintain adequate fluid and carbohydrate intake. Dehydration is a serious risk on sick days, as high blood sugar levels already cause increased urination, which depletes the body’s fluid reserves. The goal is to consume small amounts of fluid frequently, aiming for approximately 4 to 8 ounces every hour to replace lost liquids and electrolytes.
Recommended fluids include sugar-free options like water, unsweetened tea, or broth, which help with hydration without impacting blood sugar. When a person is unable to eat solid food, or if blood sugar levels are trending low, carbohydrate-containing fluids become necessary to prevent hypoglycemia. These include half a cup of regular soda, juice, or a sports drink, or consuming soft items like popsicles or gelatin.
It is necessary to ensure a continuous supply of carbohydrates, even when solid food is intolerable, to prevent the body from excessively breaking down fat and producing ketones. A good guideline is to consume approximately 15 grams of carbohydrates every one to two hours to sustain energy needs. Easily digestible, bland foods like crackers, plain toast, applesauce, or cooked cereals are good options when full meals cannot be consumed. Never stopping carbohydrate intake entirely is a crucial rule, as the body still requires glucose for functioning.
Adjusting Diabetes Medications
Managing diabetes medications during illness is complex and requires careful communication with a healthcare provider, especially since illness typically increases insulin requirements. For individuals who use insulin, the most important rule is to never stop taking basal or long-acting insulin, even if they are not eating. Stopping basal insulin is a direct path to the rapid development of DKA because the body is left without a foundational supply of the hormone.
Instead of stopping insulin, a sick person often needs to increase their dose of rapid-acting or short-acting insulin to counteract the effect of stress hormones and high blood sugar. This usually involves administering supplemental doses of rapid-acting insulin based on BG and ketone levels, in addition to the standard mealtime doses. A pre-established sick day plan should outline specific correction formulas for these supplemental insulin doses.
For individuals with type 2 diabetes who take non-insulin medications, certain drugs must be temporarily stopped immediately upon becoming ill. Specifically, Metformin should be held if the person is dehydrated, vomiting, or has severe diarrhea, as this can increase the risk of lactic acidosis. Similarly, SGLT2 inhibitors, such as canagliflozin and dapagliflozin, must be paused during an acute illness.
SGLT2 inhibitors pose a risk because they can lead to euglycemic DKA, where DKA occurs despite blood sugar levels not being severely high. These medications work by causing glucose to be excreted in the urine, and their combination with illness-related dehydration heightens the risk of complications. Consulting a healthcare provider immediately about pausing Metformin and SGLT2 inhibitors is necessary to prevent adverse outcomes.
Caution should also be exercised with over-the-counter cold and flu preparations. Many contain sugar that can elevate BG, or decongestants that can indirectly increase blood sugar levels.
Critical Warning Signs and Emergency Contact
Knowing when to seek professional medical attention is a necessary part of the sick day plan. A person should contact their healthcare provider immediately if they are uncertain about their care plan or if initial home management efforts are not succeeding.
Immediate medical attention, often requiring a visit to the emergency room, is necessary if any of the following symptoms or signs occur:
- Persistent vomiting or diarrhea: Inability to keep down fluids or food for more than six hours, or having severe diarrhea (more than five episodes).
- Ketones and high blood glucose: The presence of moderate or large ketones in the urine, or blood ketone levels above 1.5 mmol/L, especially if they do not decrease after supplemental insulin doses.
- Unresponsive high blood sugar: Blood glucose levels remaining above 300 mg/dL on two consecutive checks, despite following the sick day insulin regimen.
- Neurological changes: Experiencing confusion, severe drowsiness, difficulty waking up, or a change in ability to think clearly.
- Severe physical symptoms: Having a fever above 101°F that does not respond to fever-reducing medication, severe abdominal pain, or difficulty breathing.