In short: Insulin resistance is when the body's cells stop responding properly to insulin, so blood sugar is harder to control. It often causes no symptoms, but it raises the risk of type 2 diabetes, heart disease and fatty liver. It can usually be improved, and sometimes reversed, through weight loss, regular activity, better sleep and a balanced diet, and an HbA1c blood test helps show where you stand.

This guide, written by a Ready Health prescribing pharmacist, explains what insulin resistance is, who is at risk, how it is tested and the practical steps that help.

What is insulin resistance?

Insulin is a hormone made by the pancreas. After you eat, it helps move glucose (sugar) from your blood into your cells to be used for energy. In insulin resistance, the muscles, liver and fat cells respond less well, so the pancreas has to produce more insulin to keep blood sugar normal.

For a while this extra effort keeps things in balance. Over time, blood sugar can start to rise, first into a higher-than-normal range (often called prediabetes or non-diabetic hyperglycaemia) and then, for some people, into the type 2 diabetes range.

What are the signs of insulin resistance?

Most people have no symptoms at all, which is why it is often found only through a blood test. Possible clues include:

carrying excess weight around the waist
darker, velvety patches of skin in body folds such as the neck or armpits (acanthosis nigricans)
high blood pressure, raised triglycerides or low HDL ("good") cholesterol
polycystic ovary syndrome (PCOS)
fatty liver found on a scan or blood test

Symptoms such as feeling very thirsty, passing more urine, tiredness, blurred vision or slow-healing cuts can be signs that blood sugar has already risen into the diabetes range. If you notice these, speak to your GP promptly.

What causes insulin resistance and who is at risk?

Excess body fat, especially around the tummy and internal organs
Low physical activity and long periods of sitting
Family history of type 2 diabetes
Ethnic background: people of South Asian, Chinese, Black African or African-Caribbean heritage have a higher risk at lower body weights
Age, with risk increasing over 40 (or over 25 for some ethnic groups)
PCOS or a history of diabetes in pregnancy
Poor sleep, including untreated sleep apnoea
Some medicines, such as long-term steroid tablets

How is insulin resistance tested?

There is no single routine test for insulin resistance itself. In practice, clinicians look at your risk factors, waist measurement, blood pressure and blood tests. The most useful test is HbA1c, which reflects average blood sugar over the previous two to three months.

HbA1c result	What it usually means
Below 42 mmol/mol	Normal range
42 to 47 mmol/mol	Higher than normal (non-diabetic hyperglycaemia, sometimes called prediabetes)
48 mmol/mol or above	In the diabetes range; needs confirming and follow-up with a clinician

Cholesterol, liver function and kidney function tests are often checked at the same time.

Can insulin resistance be reversed?

In many people it can be significantly improved. Changes that make the biggest difference include:

Losing some weight if you are carrying extra: even 5 to 10% of body weight can improve blood sugar control.
Moving more: aim for at least 150 minutes of moderate activity a week. Muscle-strengthening exercise on two or more days helps muscles use glucose.
Breaking up sitting time: short walks after meals can help.
Eating well: choose wholegrains, beans, pulses, vegetables, fruit and lean protein; cut down on sugary drinks, refined carbohydrates and highly processed snacks.
Prioritising sleep and managing stress: both affect blood sugar and appetite.
Stopping smoking and keeping alcohol within low-risk limits.

If your HbA1c is in the higher-than-normal range, your GP may be able to refer you to the NHS Healthier You Diabetes Prevention Programme. For some people living with obesity and related health conditions, a prescriber may also discuss whether a medicine could help alongside lifestyle changes. Any treatment depends on an individual assessment.

Frequently asked questions

Is insulin resistance the same as prediabetes?

Not quite. Insulin resistance is the underlying problem; prediabetes describes blood sugar that has already risen above normal but not yet into the diabetes range.

Can you feel insulin resistance?

Usually not. Most people only find out through a blood test, which is why checks are worthwhile if you have risk factors.

How quickly can insulin resistance improve?

Improvements in how the body handles glucose can begin within weeks of becoming more active and losing weight. A repeat HbA1c is usually done after about three months.

Do I need to cut out carbohydrates completely?

No. Focus on the type and amount: high-fibre, wholegrain carbohydrates in sensible portions are part of a healthy diet.

Key takeaways

Insulin resistance often has no symptoms but increases the risk of type 2 diabetes and heart disease.
An HbA1c blood test is the most practical way to check your blood sugar status.
Weight loss, regular activity, good sleep and a balanced diet can greatly improve it.
If your blood sugar is raised, ask about the NHS Healthier You programme and regular monitoring.

Sources and further reading

Last reviewed: October 2026 by Shamir Patel, Independent Prescribing Pharmacist, Ready Health. This article is general information and does not replace advice from your own clinician.

If you are in Standish, Wigan or the surrounding area and are concerned about insulin resistance or your weight, book a weight management consultation at Ready Health. We can talk through your risk factors, arrange relevant blood tests and help you plan the next steps.