When a blood sugar meter displays “HI,” it indicates a very high glucose level, signaling that immediate attention is required. This reading suggests that your blood sugar has exceeded the measurable range of the device. This elevated reading prompts action to address high glucose levels.
Understanding a “HI” Reading
The “HI” displayed on your blood glucose meter stands for “High,” indicating that your blood sugar level is above the maximum limit the device can measure. For most standard glucometers, this threshold is typically above 600 milligrams per deciliter (mg/dL), or approximately 33.3 millimoles per liter (mmol/L). Some continuous glucose monitoring systems, such as certain FreeStyle Libre models, may show “HI” for readings above 400 mg/dL or 500 mg/dL, depending on the specific device. This reading signifies severe hyperglycemia. Meters display “HI” instead of a specific number at these extreme levels because the concentration of glucose is beyond their calibrated measurement capacity.
Immediate Actions to Take
Upon seeing a “HI” reading, it is important to remain calm and take immediate steps to address the elevated blood sugar. First, re-check your blood glucose level with the same meter to confirm the reading. If the “HI” reading persists, it is advisable to test for ketones in your urine or blood, especially if you have type 1 diabetes.
Begin drinking water or sugar-free fluids to help prevent dehydration, which can worsen high blood sugar. If you use insulin, administer a correction dose as advised by your healthcare provider. Contact your doctor or diabetes care team right away for further guidance.
Common Reasons for Extremely High Blood Sugar
Extremely high blood sugar can stem from several factors. A common cause is missed or insufficient doses of diabetes medication or insulin, which prevents glucose from entering cells effectively. Illnesses and infections, such as the flu, a cold, or a urinary tract infection, can significantly raise blood sugar levels as the body releases stress hormones to fight the infection. Emotional and physical stress can also trigger a surge in glucose, as the body’s “fight or flight” response affects insulin sensitivity.
Certain medications, including corticosteroids and some diuretics, are known to elevate blood glucose as a side effect. Consuming too many carbohydrates or sugary foods without adequate insulin or medication to process them can lead to a sharp rise in blood sugar. For individuals using insulin pumps, a malfunction or dislodged tubing can interrupt insulin delivery. Other factors, like growth spurts, menstruation, or even a heart attack or stroke, can also contribute to high blood sugar.
When to Seek Urgent Medical Attention
Recognizing when to seek urgent medical attention is crucial, as high blood sugar can lead to serious complications like diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS). Symptoms that warrant an immediate trip to the emergency room for DKA include persistent nausea, vomiting, abdominal pain, and a distinct fruity odor on your breath. Rapid, deep breathing, confusion, and extreme tiredness are also signs of DKA. If your ketone levels are significantly high, such as over 3 mmol/L in blood, immediate medical help is needed.
For HHS, which often develops more gradually, symptoms can include extreme dehydration, severe confusion, disorientation, or even loss of consciousness. Weakness, leg cramps, and vision problems may also occur. HHS is characterized by very high blood sugar levels, typically above 600 mg/dL (33.3 mmol/L), without significant ketone production. If you experience any of these symptoms alongside a “HI” blood sugar reading, do not delay in seeking emergency care.
Strategies for Long-Term Management
To prevent future “HI” readings and maintain stable blood sugar levels, consistent long-term management strategies are important. Regularly monitoring your blood sugar with a meter or continuous glucose monitor helps you understand how your body responds to food, activity, and medication. Adherence to your prescribed medication or insulin regimen is crucial for glucose control. Eating a balanced diet with controlled portions of carbohydrates and engaging in regular physical activity are also important for glucose control.
Developing a sick-day plan with your healthcare provider is essential, outlining how to adjust medication and monitor blood sugar and ketones during illness. Stress management techniques can help mitigate stress-induced blood sugar spikes. Regular follow-up appointments with your diabetes care team, including endocrinologists, dietitians, and diabetes educators, provide ongoing support and allow for necessary adjustments to your treatment plan. Education about your condition and proactive management helps prevent severe hyperglycemia.