Living with low sugar

Overview

Low blood sugar, also called hypoglycaemia, happens when the amount of glucose (sugar) in your blood drops below the level your body needs to work normally. Glucose is the main fuel for your brain and muscles. When it falls too low, you may feel shaky, sweaty, confused, or weak. It can happen to people who take certain diabetes medicines, but it can also occur for other reasons. It is usually treatable quickly, but severe episodes need urgent help.

Yes. Hypoglycaemia is common, especially in people with diabetes who use insulin or certain other glucose-lowering medicines. It can also happen in people without diabetes, though less often.

It most often affects people with diabetes, particularly those taking insulin or certain diabetes tablets. However, anyone can experience low blood sugar — for example, after a long period without food, after heavy alcohol use, or as part of a rare medical condition.

Symptoms

Common symptoms

• Shaking or trembling
• Sweating
• Feeling hungry
• Fast or pounding heartbeat
• Feeling anxious, irritable, or tearful
• Dizziness or light-headedness
• Headache
• Weakness or tiredness
• Blurred vision
• Difficulty concentrating

Symptoms in children

• In children, low blood sugar may cause mood changes, crying, irritability, being unusually quiet or clingy, pale skin, or a sudden temper.

Symptoms in older adults

• Older adults may have fewer warning signs or different ones. They might feel confused, drowsy, unsteady, or have slurred speech. Falls, dizziness, or simply 'not feeling right' can be the only clue.

Causes

Main causes

• Taking too much diabetes medicine (especially insulin or certain diabetes tablets)
• Skipping or delaying meals
• Not eating enough carbohydrate for the amount of insulin or activity
• Drinking alcohol without food, especially on an empty stomach
• Unusually strenuous or long exercise
• Some other medicines or medical conditions, such as liver, kidney, or hormone problems

Risk factors

• Having diabetes and using insulin or certain diabetes tablets
• Following very tight blood sugar targets
• Missing or delaying meals
• Drinking alcohol, especially without food
• Exercising more than usual
• Being older and living alone
• Having long-standing diabetes or a history of severe lows
• Having kidney or liver problems

When to see a doctor

See a doctor urgently if:

• If you have low blood sugar that does not improve after treating it according to your care plan
• If you have repeated lows and are not sure what is causing them
• If you feel too confused or sleepy to treat yourself
• If you are on diabetes medicines and have a severe low that needed someone else's help

Book a routine appointment if:

• If you are having mild low blood sugar episodes more than two or three times a week
• If you have symptoms of low blood sugar but your blood sugar measurements are normal
• If you have diabetes and your blood sugar levels are swinging widely
• If you have started a new medicine and think it may be causing lows

Diagnosis

Low blood sugar is diagnosed by checking your blood glucose level with a finger-prick meter or a continuous glucose monitor. Your healthcare provider will also ask about your symptoms, when they happen, and what you were doing before an episode. They will want to see how your body responds to treatment.

Tests that may be done

• Finger-prick blood glucose test using a hand-held meter
• Continuous glucose monitoring over a few days if needed
• Laboratory blood test for glucose, sometimes after fasting
• Tests for insulin and other hormones if the cause is unclear
• A supervised fast or mixed-meal test in rare cases

What to expect at your appointment

You may be asked to keep a diary of your blood sugar readings, meals, and activity. Your doctor or diabetes nurse may review your medicines and suggest adjustments. If you do not have diabetes, you may need extra tests to look for other causes. It can take time, but most people find a plan that works.

Treatment

The immediate treatment for low blood sugar is to raise your blood glucose quickly with a fast-acting carbohydrate. Your healthcare team can then help you prevent future episodes. The right long-term plan depends on the cause — it may include adjusting medicines, changing meal patterns, or treating an underlying condition.

Self-care at home

• Carry a fast-acting carbohydrate with you, such as glucose sweets, a sugary drink, or juice
• Check your blood sugar if you can, but if you feel low and cannot check, treat it anyway
• Follow your healthcare team's plan for treating a low — usually a fast-acting carbohydrate followed by a longer-acting snack
• Tell family, friends, or colleagues how they can help if you become confused or unable to treat yourself
• Keep a record of your lows so you and your team can spot patterns

Medical treatments

For people with diabetes, the main medical treatment is adjusting diabetes medicines to reduce the chance of lows. Your doctor or diabetes nurse may change the type or timing of your medicine. If low blood sugar is caused by another medical condition, that condition will be treated. In severe emergencies, a healthcare professional or trained family member may give an injection that raises blood sugar quickly. This is only used in emergencies, not as a routine treatment.

When is surgery considered?

Surgery is not a treatment for low blood sugar itself. However, if an underlying condition such as an insulinoma (a rare, usually non-cancerous insulin-producing tumour in the pancreas) is causing the lows, surgery may be recommended to remove it. This decision is always made by specialists after careful testing.

Living with this condition

Living with low blood sugar means learning to recognise your early warning signs, being prepared, and having a clear plan. Most people learn to manage it well. The key is to build routines that keep your levels steadier — regular meals, balanced carbohydrates, consistent activity, and careful medicine timing if you have diabetes. It can feel overwhelming at first, but over time it becomes second nature.

Lifestyle tips

• Eat regular meals and snacks if your healthcare team advises
• Do not skip meals, especially if you take glucose-lowering medicines
• Carry hypo treatments wherever you go — in your bag, car, and workplace
• Wear a medical ID or carry a card saying you have diabetes or are at risk of low blood sugar
• Tell the people close to you how they can help in an emergency

Diet and exercise

Eating balanced meals with some slow-release carbohydrate, such as whole-grain bread, oats, or pulses, can help keep levels steadier. Avoid long gaps without food. Check your blood sugar before and after exercise if you can, and have a snack if needed. Your healthcare team or a dietitian can help you match food, activity, and medicine. If you do not have diabetes, a dietitian can help you find a pattern of eating that avoids lows.

Mental health and emotional wellbeing

Worrying about low blood sugar is normal. Many people feel anxious about it happening in public or while sleeping. This can be exhausting. It can help to talk to your healthcare team about your fears and to consider peer support. If you are living with diabetes, you may also be at higher risk of depression. If you are having thoughts of self-harm or suicide, please contact a crisis support line or your local emergency services right away.

Prevention

Many episodes of low blood sugar can be prevented by matching medicines, food, and activity. If you have diabetes, work with your team to review your blood sugar targets and medicine. If you do not have diabetes, identifying triggers and eating regular, balanced meals will reduce your risk. You may not be able to prevent every episode, but you can reduce how often they happen and how severe they are.

Screening programmes

If you have diabetes, checking your blood sugar as recommended by your healthcare team is the best way to catch lows early. If you do not have diabetes, routine screening is not needed unless you have symptoms or risk factors.

Complications

If left untreated

• Falls or accidents caused by dizziness or confusion
• Severe low blood sugar leading to loss of consciousness or seizures
• Impaired awareness of hypoglycaemia — when you stop feeling the early warning signs
• Repeated severe episodes can affect memory and thinking, especially in older adults
• Rarely, very low blood sugar can cause heart rhythm problems

Long-term outlook

With the right support, most people with low blood sugar lead full, active lives. You can learn to spot the early signs, treat them safely, and often prevent future episodes. Even after a severe episode, most people recover fully. Your healthcare team can help you build confidence and a plan that works for you.

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