Free Diabetes TrackerSign in
Get help

When to get help

What to do about a hypo, or a very high reading with ketones. This follows NHS and Diabetes UK advice. Always follow any personal “sick-day rules” or instructions your own diabetes team have given you.

Call 999 or go to A&E now

For a severe hypo – if the person:

  • is unconscious or cannot be woken
  • is having a seizure (fit)
  • is so confused they cannot safely swallow

Do not put food or drink in the mouth of someone who is not fully awake. Put them in the recovery position. If a glucagon injection kit is to hand and you are trained to use it, give it.

For diabetic ketoacidosis (DKA) – a high reading with any of:

  • feeling or being sick
  • tummy (stomach) pain
  • breathing more deeply or quickly than usual
  • breath that smells fruity, like pear drops
  • feeling very drowsy or confused
  • blood ketones over 3 mmol/L (or 2+ on a urine test)
Call 999

Contact your diabetes team or NHS 111

Get advice the same day if:

  • your blood ketones are 1.6 to 3 mmol/L
  • your blood sugar stays high and you feel unwell, or you are unwell and unsure what to do
  • you are having repeated hypos, or a hypo that will not come back up after treating it twice
  • you are being sick and cannot keep fluids down (your blood sugar can change quickly)
Call 111

Treating a hypo (below 4 mmol/L)

Remember “4 is the floor”. If your blood sugar is below 4:

  1. Have 15 to 20g of fast-acting carbohydrate – for example 4 to 5 glucose tablets, a small glass (150 to 200ml) of a sugary (non-diet) drink or fruit juice, or 4 to 5 jelly babies.
  2. Wait 10 to 15 minutes, then check your blood sugar again.
  3. If it is still below 4, repeat the fast-acting carbohydrate.
  4. Once you are back above 4 and feel better, if your next meal is not due soon, have a longer-acting carbohydrate such as a slice of toast, a sandwich or a piece of fruit.

Do not treat a hypo with chocolate or biscuits first – the fat slows the sugar down. More detail: Hypos (low blood sugar).

High blood sugar and ketones

A single high reading is usually not an emergency – look for a pattern over a few days and follow your team's advice. But if you have type 1 and your blood sugar is high (around 15 mmol/L or more) and/or you feel unwell, check for ketones. Blood ketones of 0.6 to 1.5 mmol/L are slightly raised – test again in a couple of hours; 1.6 to 3 means you are at risk of DKA and should get advice; over 3 is an emergency. More detail: Highs and ketones.

If you are unwell

Being ill often pushes blood sugar up. Do not stop your insulin without advice, keep drinking sugar-free fluids, check your blood sugar (and ketones, if you have type 1) more often, and follow any sick-day rules your team gave you. Get advice if you are not sure what to do.

If you are pregnant

Blood sugar targets are tighter in pregnancy and are supervised by your maternity and diabetes team. Contact them if your readings keep falling outside the targets they set, or if you feel unwell. See Diabetes in pregnancy.