Emergency Protocol: When to Go to the Hospital for High Sugar

If you've ever checked your meter and seen "300," you may be wondering, "Blood sugar 300 what to do?" A reading of 300 mg/dL or higher is well above normal and requires prompt attention. This guide walks you through practical steps to take right away, signs that you need emergency care, and when to call your doctor.

Why a Blood Sugar of 300 mg/dL Matters

• Normal fasting blood sugar: 70–99 mg/dL
• Normal post-meal (2 hours): under 140 mg/dL
• 300 mg/dL: three times higher than normal fasting levels

At this level, your body may be short on insulin or unable to use it effectively. High blood sugar (hyperglycemia) can cause dehydration, ketoacidosis (especially in type 1 diabetes), and other serious complications if not addressed.

Immediate Steps to Take if Your Blood Sugar Is 300

When you see a blood sugar reading of 300 mg/dL, follow these steps:

1. Stay Calm and Re-test

   • Wash your hands; retest to confirm the reading isn't a meter error.
   • If it's still 300 or higher, move on to the next steps.

2. Hydrate

   • Drink 16–20 ounces of water over the next hour.
   • Fluids help flush excess sugar through your kidneys.

3. Take Fast-Acting Insulin (if prescribed)

   • Calculate correction dose per your doctor's plan:
     • Correction factor (e.g., 1 unit lowers BG by 50 mg/dL)
     • Example: (300 – 120) ÷ 50 = 3.6 → round to 4 units
   • Administer under guidance from your diabetes care team.

4. Check for Ketones (Type 1 Diabetes or Insulin Deficiency)

   • Use urine strips or a blood ketone meter.
   • If moderate to large ketones are present, you're at risk for diabetic ketoacidosis (DKA).

5. Adjust Diet and Activity

   • Avoid fast-absorbing carbs (sweets, juice).
   • A light walk can help lower sugars—only if you feel well and your ketones are negative.

6. Monitor Frequently

   • Recheck every 1–2 hours until levels are below 250 mg/dL.
   • Record readings, insulin doses, food, exercise, and symptoms.

When to Seek Emergency Medical Care

Even with home management, certain signs mean you should head to the ER or call 911:

• Persistent high sugars
– Readings above 300 mg/dL that don't improve after 2–3 correction doses
• Signs of Diabetic Ketoacidosis (DKA)
– Fruity breath odor
– Rapid, deep breathing
– Nausea, vomiting, or abdominal pain
– Confusion or drowsiness
• Signs of Hyperosmolar Hyperglycemic State (HHS)
– Extreme dehydration (dry mouth, sunken eyes)
– Very low urine output
– Severe weakness or confusion
• Severe Symptoms
– Chest pain or difficulty breathing
– Slurred speech, drooping face, sudden weakness (stroke signs)
– Inability to keep fluids down

If you experience any of the above, do not delay—call 911 or go to your nearest emergency department. These conditions can progress rapidly and become life-threatening.

Warning Signs That Warrant a Call to Your Doctor

Even if you don't need an ambulance, contact your healthcare provider if you notice:

• Blood sugar readings persistently above 250 mg/dL for more than 24 hours
• Frequent ketones or repeated DKA episodes
• Severe dehydration that doesn't improve with fluids
• Significant changes in weight or appetite
• New or worsening vision problems, numbness, or tingling
• Any feeling that something is seriously wrong

Your doctor may adjust your medication, advise a different insulin regimen, or order lab tests to check kidney function, electrolytes, and blood counts.

Practical Tips to Avoid Future Spikes

Managing high readings today helps you prevent them tomorrow:

• Follow a consistent meal plan
– Balance carbs, protein, and healthy fats
– Use carb counting or plate method guidance
• Keep an eye on Hidden Carbs
– Sauces, dressings, and beverages can spike sugars
• Maintain an exercise routine
– Aim for at least 30 minutes most days—walking, cycling, swimming
• Store Insulin Properly
– Room temperature up to 28 days after opening
– Discard if exposed to extreme heat or cold
• Monitor Stress and Illness
– Stress hormones and infections raise blood sugar
– Check more often during sickness
• Stay on Top of Appointments
– Regular A1C tests, eye exams, foot checks

Use Tools to Stay Informed

If you're experiencing concerning symptoms alongside elevated readings, you can check your symptoms with a free AI-powered assessment for High blood sugar (hyperglycemia) to get personalized guidance on whether to manage at home or seek immediate medical attention.

Speak to a Doctor for Serious Concerns

High blood sugar can escalate quickly. If you ever feel that your situation might be life-threatening—chest pain, severe dehydration, persistent vomiting, extreme confusion—call 911 or go to the nearest ER immediately. For non-emergencies, your primary care physician or diabetes specialist is your best resource.

Bottom Line: Blood Sugar 300 What to Do

A blood sugar reading of 300 mg/dL is a clear sign to act:

1. Confirm with a retest.
2. Hydrate, correct with insulin per your plan, and check ketones.
3. Monitor every 1–2 hours until levels drop below 250 mg/dL.
4. Seek emergency care if you see DKA or HHS warning signs.
5. Call your doctor for persistent or severe issues.

Keeping a cool head, following a clear action plan, and knowing when to get help will keep you safe and reduce the risk of complications. Always follow your healthcare team's instructions, and never hesitate to seek professional care if you're concerned about your health.