Dealing with Extremely High Blood Sugar Levels

When you're living with diabetes, you get to know your numbers blood sugar readings can guide everything from your meals to your mood. But what happens when that number skyrockets above 400 mg/dL? This level of hyperglycemia isn’t just a red flag it can be a sign of a serious, even life-threatening complication. Here's how to recognize the warning signs and what you should do next.

Understand Your Numbers

The American Diabetes Association recommends the following blood sugar targets:

• Before meals: 80–130 mg/dL

• After meals: Below 180 mg/dL

But when your glucose reading hits 400 mg/dL or higher, it's no longer just about being above your goal it could mean your body is in distress. While not everyone will have symptoms at this level, you should treat it as a potential emergency.

Step One: Re-Test Immediately

Before you panic, double-check the result. False highs can happen due to:

• Sugar or food residue on your fingertips

• Expired or improperly stored test strips

• Device malfunction

Wash your hands and re-test to confirm the number.

Step Two: Call Your Doctor

If the second reading is still over 400 mg/dL, contact your healthcare provider right away. Depending on your care plan, they might advise:

• Adjusting your insulin or medication

• Drinking water to help flush excess glucose

• Testing for ketones

Always follow your provider’s instructions even if you’re not feeling symptoms.

Step Three: Check for Ketones

If your blood sugar is above 240 mg/dL, the ADA recommends checking your urine for ketones. High levels can indicate diabetic ketoacidosis (DKA), a serious complication that happens when your body starts breaking down fat for energy due to a lack of insulin.

Signs of DKA include:

• Fruity-smelling breath

• Rapid, deep breathing

• Nausea or vomiting

• Fatigue

• Dry skin or mouth

• Stomach pain

• Headache or confusion

If you have ketones or any of the above symptoms, seek medical attention immediately. Exercise is not recommended at this point it can worsen the situation by raising blood sugar even more.

Step Four: Know When to Call 911

You don't have to wait for all the symptoms to appear. If you're experiencing any signs of DKA, or if your blood sugar stays dangerously high despite taking corrective action, go to the emergency room or call 911. Hyperglycemia can progress rapidly, and DKA can be fatal if left untreated.

What Causes Blood Sugar Spikes Over 400?

Several factors can trigger extremely high blood sugar, including:

• Skipping insulin or taking too little

• Consuming more carbohydrates than your medication can handle

• Lack of physical activity

• Illness or infection

• Emotional or physical stress

• Medications like steroids, beta-blockers, or certain contraceptives

• The dawn phenomenon (a hormonal blood sugar spike in the early morning)

How to Prevent Future Spikes

Staying ahead of blood sugar surges takes a proactive approach. Here are some everyday habits that can help:

• Avoid sugary drinks: Soda, juice, and sweetened coffee drinks can cause quick spikes. Opt for water or unsweetened beverages.

• Choose complex carbs: Foods like lentils, quinoa, and whole-grain bread release sugar more slowly than simple carbs.

• Eat balanced meals: Pair carbohydrates with protein and fiber-rich vegetables to stabilize glucose levels.

• Stay active: Aim for at least 150 minutes of moderate exercise per week, such as walking or swimming.

• Track your numbers: Regular monitoring can catch rising trends before they become dangerous.

• Reduce stress: Chronic stress can interfere with blood sugar control. Mindfulness, yoga, or even five deep breaths can make a difference.

• Quit smoking: Smoking can increase blood sugar and insulin resistance. Stopping can improve not only your diabetes but your overall health.

Your Safety Comes First

Whether you’re managing type 1 or type 2 diabetes, a blood sugar reading over 400 mg/dL should never be ignored. Know your plan, listen to your body, and act fast when things feel off. Share this article or subscribe to our newsletter for more wellness insights.