3 Dangers of Skipping Mealtime Insulin

Medically Reviewed By William C. Lloyd III, MD, FACS
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Rapid-acting mealtime insulin can help those with diabetes keep their blood glucose levels (also known as blood sugar levels) from rising too high after they eat. It’s often recommended for people who can’t achieve their target levels by only taking background insulin once a day. Mealtime insulin is usually taken 10 to 30 minutes before a meal and lasts for four to six hours, depending on the insulin type. Examples of mealtime insulin include insulin aspart (NovoLog), insulin lispro (Humalog), and insulin glulisine (Apidra).

If you miss a mealtime dose, there’s no need to panic, but it’s important to understand the situation could get serious. Be sure you know your next steps based on your diabetes treatment plan. Always stick with your current diabetes treatment, follow the advice of your doctor, and renew your prescriptions. If you do miss a dose, depending on your doctor’s guidance, next steps could be as simple as taking a corrective insulin dose or eating a certain number of carbohydrates. In case your symptoms become severe and you need help managing them, you may also want to carry a medical alert ID or wear a bracelet. When it comes to taking mealtime insulin, timing is everything. Understand what can happen—and what to do—when your clock is off.

1. Diabetic Ketoacidosis (DKA)

The most serious risk of missing a dose of mealtime insulin is diabetic ketoacidosis (DKA). When your blood glucose levels get too low, your body can’t use glucose for energy. Your body starts breaking down fat instead, causing acids called “ketones” to build up in your blood stream. In the worst cases, DKA can cause coma and even be fatal. The Centers for Disease Control and Prevention (CDC) show that 188,000 people with diabetes in the United States were hospitalized for DKA in 2016.

Symptoms of DKA include:

If you experience these symptoms, check your blood glucose levels right away. You can also check your ketone levels with a urine test from your drug store. If your symptoms don’t respond to the correction dosage of insulin your doctor has prescribed, seek emergency medical attention. Blood glucose levels that stay above 300 mg/dL put you in the danger zone.

2. Hypoglycemia (Low Blood Sugar)

According to the CDC, nearly a quarter of a million people with diabetes in the U.S. were hospitalized for hypoglycemia in 2014. Hypoglycemia is a dangerous condition that happens to diabetics when the level of glucose in the blood falls below the target a doctor has set. Glucose is the body’s main source of energy. For many of those with diabetes, “too low” is a blood glucose level of 70 mg/dL or lower.

Hypoglycemia can happen fast. It doesn’t always have symptoms, but common ones are:

  • Hunger
  • Shakiness
  • Blurred vision
  • Weakness
  • Paled skin

Hypoglycemia is not to be taken lightly. The following symptoms can indicate a severe drop in blood sugar levels. If you experience any of these symptoms, seek immediate medical attention:

  • Inability to eat or drink
  • Loss of consciousness

3. Hyperglycemia (High Blood Sugar)

More than 200,000 people with diabetes were hospitalized for hyperglycemic crisis in 2016, according to the CDC. Hyperglycemia occurs when the glucose in your blood rises too high.  For many people with diabetes, “too high” is a blood glucose level of 200 mg/dL or higher.

Unlike hypoglycemia, hyperglycemia doesn’t usually come on quickly. Symptoms may take days or weeks to develop, if they develop at all. If you do have symptoms, they will likely become more severe the longer your blood glucose level is elevated.

Common symptoms of hyperglycemia are:

  • Headache

If hyperglycemia goes on too long without treatment, it can lead to serious complications, including damage to your kidneys, heart, nerves, and eyes. Don’t hesitate to let your doctor know when you’re concerned.
So what’s the good news? Nearly 30 million people in the U.S. are living with diabetes, and diabetes management is getting better. You are your own best friend in achieving good control. Know your body, check your levels, manage your prescriptions, and partner with a doctor you can count on for an ongoing dialogue about how you’re doing.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2022 Aug 29
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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