Hypoglycaemia: a low blood sugar emergency case guide

The case: a sudden hypo

Meet "Sara", a fictional 27-year-old who has type 1 diabetes and uses insulin. One afternoon, after a busy morning and a smaller lunch than usual, she suddenly feels shaky, sweaty and very hungry. Her heart is racing, she feels anxious, and she finds it hard to concentrate on her work. A colleague notices she has gone pale and is fumbling her words. Sara recognises these as early warning signs of a hypo. This pattern — a fast onset of shakiness, sweating, hunger and difficulty thinking — is typical, and the early symptoms are the body's alarm telling her to act quickly before the low blood sugar affects her brain more seriously.

Recognising the warning signs

Hypo symptoms come in two waves. The early, adrenaline-driven signs include shaking, sweating, a pounding heart, hunger, tingling lips, anxiety and looking pale. If sugar keeps falling, brain symptoms appear: confusion, slurred speech, difficulty concentrating, unusual or aggressive behaviour, blurred vision, drowsiness and clumsiness. Some people, especially after many years of diabetes, lose their early warnings and can drop low without much notice, which is more dangerous. Symptoms can also appear at night as restless sleep, sweating or a headache on waking. Family, friends and colleagues can be the first to spot that someone is behaving oddly, so it helps if the people around a person with diabetes know what a hypo can look like.

First aid: eat or drink fast sugar

If someone with a hypo is awake and able to swallow safely, the treatment is fast-acting sugar straight away. Good choices include a small glass of a sugary (non-diet) drink, a few glucose tablets, or a tube of glucose gel. Sara drinks some orange juice and sits down to rest. After about ten to fifteen minutes she checks again; if she still feels low or her meter is still low, she takes another portion of fast sugar. Once she feels better, she has a longer-lasting snack such as a sandwich or biscuits to stop the sugar dropping again. Chocolate is a poor first choice because the fat slows the sugar down. Most hypos are fixed at home with this simple sequence.

When a hypo becomes a 999 emergency

A hypo becomes an emergency when the person can no longer help themselves. Call 999 immediately if someone with a low blood sugar becomes unconscious, is having a seizure (fit), or is too confused or drowsy to swallow safely. Do not try to put food or drink into the mouth of someone who is not fully awake, because it can choke them. Instead, put them in the recovery position and stay with them until help arrives. Some people carry an emergency glucagon injection or nasal spray that a trained family member can give while waiting for the ambulance. After any severe hypo, the person should be reviewed so their diabetes treatment can be adjusted to prevent it happening again.

Preventing the next hypo

Once recovered, the useful question is why the hypo happened, because most have a reason. Common triggers are too much insulin or diabetes medicine, a missed or delayed meal, more exercise than usual, and drinking alcohol, especially without food. People at risk are encouraged to check their glucose regularly, carry fast sugar at all times, and wear or carry medical identification. Continuous glucose monitors, now widely available on the NHS for many people with type 1 diabetes, can alert users before they drop too low. Anyone having frequent hypos, or who has lost their early warning signs, should speak to their diabetes team, who can review medicines, targets and technology to make future hypos less likely and less severe.