What To Do If Your Blood Sugar Spikes or Crashes: A Quick Response Guide
- Jun 13, 2025
- 3 min read
Updated: Sep 3, 2025
Ever felt shaky, dizzy, or extremely tired out of the blue? These could be signs that your blood sugar has either spiked or crashed. Knowing how to quickly respond is vital – especially if you're managing diabetes.
This guide offers a simple, fast-acting plan to help you stay safe and regain balance.
Whether you live with Type 1 or 2 diabetes, this quick response guide to blood sugar highs and lows is something every person and their loved ones should know.
What happens when blood sugar spikes?
A blood sugar spike (hyperglycaemia) means your blood glucose levels are too high, usually above 180 mg/dL (10 mmol/L). This might happen after a meal high in carbs or sugar, or if insulin or medication was missed.
Common signs of a spike:
Frequent urination
Extreme thirst
Blurred vision
Fatigue
Headache
Quick actions for high blood sugar:
Check your blood sugar level to confirm
Stay hydrated - drink water to help flush out excess glucose
Take insulin (if prescribed) - follow your correction dose guidelines
Go for a light walk - gentle movement can help lower glucose
Avoid carbs and sugar until your level is stable
Call your healthcare provider if blood sugar remains high for several hours or if you're vomiting.
What happens when blood sugar crashes?
A blood sugar crash (hypoglycaemia) means your levels have dropped below 70 mg/dL (3.9 mmol/L). This can happen if you skipped a meal, over-exercised, or took too much insulin or medication.
Common signs of a crash:
Shaking or trembling
Sweating
Confusion or brain fog
Irritability
Rapid heartbeat
Dizziness
Quick actions for low blood sugar (The 15 Rule):
Check your blood sugar to confirm it's low
Consume 15g of fast-acting sugar, such as 1/2 cup of juice or regular soda, 1 tablespoon of honey or jam, or 3-4 glucose tablets
Wait 15 minutes, then recheck your blood sugar
If still low, repeat the 15g treatment
Once normal, eat a small snack with carbs and protein (e.g., toast with peanut butter) to maintain stability
Want to know more about how our service works for people managing diabetes? Our team is here to explain the next steps.
Take control of your diabetes today
Don’t wait for a spike or crash to take action. Being prepared — with the right knowledge, supplies, and support — can make all the difference.
Managing diabetes is easier with the right support. With discreet NHS prescription deliveries and reliable access to your supplies, getting started is quick and simple.
Frequently Asked Questions: Blood Sugar Spikes and Crashes
1. What causes blood sugar to spike?
Common causes include high-carb meals, stress, illness, or missing insulin doses.
2. What if I don't have glucose tablets for a crash?
Use simple sugars like fruit juice, honey, or regular soda (not diet).
3. Should I go to hospital after a sugar crash?
If you're confused, unconscious, or your sugar won't rise after repeated treatments – call emergencies services.
4. Can I get my CGM device and supplies through Rapidcare?
Yes! If your Continuous Glucose Monitor (CGM) is prescribed by your NHS healthcare provider, Rapidcare can support you with stress-free prescription deliveries, nurse referral where needed, and discreet, reliable service tailored to your medical needs.
5. What should my emergency kit include?
Glucose tablets or gel
Spare insulin and needles
CGM or glucose meter
Emergency contacts
Snacks (like granola bars)
For more information on managing diabetes, read: Health and Diabetes: How to Manage the Impact of Sugar
