Hypos: their symptoms and causes

What are hypos?
  • Hypos (hypoglycaemia) are the result of glucose in the blood falling to a low level (less than 4mmol/l).  Hypos occur most commonly in people with diabetes.
  • Hypos are one of the most common diabetes complications experienced by those treated with sulphonylureas or insulin.
What are the symptoms?
  • Hypo symptoms are different for everyone, but they can include: pounding heart, trembling, hunger, sweating, difficulty concentrating, irritability or blurred vision.
  • If you experience a particularly severe hypo, you may lose consciousness and will need help from another person to treat your symptoms.
  • Night-time (nocturnal) hypos, which often occur when a person is asleep, can be a particular concern for people with diabetes as they are unpredictable and hard to detect.  Symptoms of night-time hypos include waking up with a morning headache, night sweats and extreme tiredness.
What causes hypos?
  • You might experience a hypo because you have excess insulin, missed a snack or meal, are not eating enough carbohydrate, do unplanned exercise, or if you are drinking alcohol without food.  However, sometimes there is no obvious reason.
  • There may also be other reasons why you have experienced symptoms similar to that of a hypo, so it is important to speak to your healthcare professional to be sure.


Experiencing hypos?

It's important to speak with a healthcare professional if you are experiencing hypos or if you have any questions about them.  Download the Hypo Journal  to help you track any symptoms you experience or any potential triggers month by month.  Bring this journal to your next appointment to discuss with your doctor or nurse.



This page is intended for members of the UK public
UK/WB/0516/0015(1)  September 2016

How to treat a hypo

For information on steps that can be taken to help manage hypos

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Below the Surface

Watch the Below the Surface films to learn more about the varying symptoms of hypos

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Practical information and resources

Download the Hypo Journal and find out where to access more information on hypos

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Hypo Hub

Access information, resources and practical guidance on how to manage hypoglycaemia (hypos)

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