Not being able to recognise the warning signs of a hypo, also called hypoglycaemia, affects some people with diabetes. It can be dangerous.
Not everyone with diabetes will have hypos you’re more at risk of hypos if you take insulin or certain other diabetes medications like sulphonylureas.
What is hypoglycaemia (hypo) unawareness?
A hypo is when your blood sugar, also known as blood glucose level, drops too low, below 4mmol/l.
Hypo unawareness is when you can’t spot the signs that you are having a hypo. It can occur in people that treat their diabetes with insulin or sulphonylureas. You will only know if your blood sugar is low by checking your level.
If you're unaware of your blood sugar dropping dangerously low, then you can't treat the hypo quickly. This means you can’t get back into your normal blood sugar range and this increases the risk of a severe hypo.
Your quality of life is usually affected, and it can be hard to keep your blood sugar levels in a safe range. You will have to stop driving and it can affect your work, social life and home life.
What causes hypoglycaemia (hypo) unawareness?
We know that if you have lots of hypos, you’re more likely to stop noticing the symptoms over time.
We don’t yet fully understand why people are unaware of hypos.
But you're more likely to be unaware of hypos if you:
- have type 1 diabetes
- have had diabetes for a long time and have always tended to have episodes of low blood sugar
- are trying to manage your blood sugars within a very tight range, especially at the lower end of a target range
- If you have problems with memory, learning or mental health difficulties, such as severe depression, it can also be harder to manage your diabetes.
What treatment is there for hypoglycaemia (hypo) unawareness?
If you think you’re losing your hypo awareness, speak to your diabetes team. They can work with you to find out what might be causing this and help you get your awareness back. They may also be able to refer you to a specialist in hypo unawareness if needed. You can also read our hypo anxiety page which has tips on managing hypo anxiety.
Getting your hypoglycaemia (hypo) awareness back
If you can avoid hypos for a few weeks, your awareness may return. Your diabetes team can help you with this.
They may suggest checking your blood sugar levels more often, adjusting your medication, or relaxing your blood sugar targets for a while.
Raising blood sugar levels for a while can help some people get back their awareness of hypoglycaemia. But do not do this without speaking to your team. They can advise you on what blood sugar level you should aim for and for how long.
Continuous glucose monitor (CGM)
If you find that you're no longer noticing the signs of low blood sugar, a CGM could help. A CGM lets you check your sugar levels more often, without having to prick your fingers. Your latest sugar levels show up on a device or mobile automatically, transmitted by Bluetooth. If you use a FreeStyle Libre 2, this is now a real-time CGM too, although you can still scan the sensor to see your glucose readings if you want to.
With a CGM, you can set an alarm to sound if your blood sugar levels are dropping too low. This means you can be warned at any time of the day or night about any hypos, just before or as they start happening. This gives you time to prevent the hypo or treat it sooner.
Talk to your diabetes team about this type of monitor if you don't already have one. We have information on who is eligible for diabetes tech.
“It was a bit of a worry not having feelings of high or low blood sugar. But with the CGM if my blood sugar level goes below 4mmol or above 10mmol it bleeps and it gives you a chance to do something about it. Read Anne's story.
Islet transplants
A small number of people who have severe hypos and hypo unawareness can be referred for islet transplants. This is when insulin-producing cells from a donor are transplanted into your pancreas.
Bruce had an islet transplant in 2014. Read Bruce's story to find out more.
Get support
For more advice and support about hypo unawareness, talk to your healthcare team.
Or if you'd rather talk over the phone, our helpline is managed by advisors who are ready to answer your questions or just listen.
You can also reach out on our forum to others with diabetes who have experienced hypo unawareness.
