Metabolic Syndrome

Metabolic syndrome is the name given to a group of health problems that puts you at higher risk of diseases of the heart and blood vessels, including heart attacks and stroke. It's very common, around one in four adults in the UK are thought to have the metabolic syndrome. 

The health problems that make up the metabolic syndrome are sometimes called risk factors. These risk factors are:

  • high blood pressure
  • insulin resistance – where the hormone insulin is less able to keep the amount of sugar in the blood at a healthy level
  • overweight or obesity – especially around the waistline
  • unhealthy levels of blood fats – usually high triglyceride levels and low HDL levels.

This group of health problems has been known for many years. It was first called “metabolic syndrome” back in 1988. Having three or more of these risk factors usually suggests a person has metabolic syndrome.

Insulin resistance

Insulin is a hormone that is made in the pancreas. It helps to control the amount of sugar in the blood. If you have insulin resistance, your body can't respond properly to the insulin made in your pancreas so it has to make more and more to cope with the build-up of sugar in the blood.

Over time, the pancreas is put under more and more pressure to make insulin. Eventually the strain can become too much. The pancreas won't be able to make enough insulin and the cells which make insulin can become exhausted. The levels of sugar in the blood rise and stay high. This is called type 2 diabetes.

Why are insulin resistance and diabetes dangerous?

When your blood sugar levels are too high, the sugar damages your blood vessels. This can lead to eye problems and nerve damage and kidney damage, which can all be very serious. Diabetes also raises the risk of heart disease and blood vessel diseases, including heart attacks and strokes. 

It can be treated with medicines to help your liver produce less glucose, and to make your body more sensitive to insulin. Lifestyle changes including a healthy diet and exercise can also make a huge difference. 

How are insulin resistance and diabetes diagnosed? 

Doctors have special guidelines for diagnosing diabetes. This usually involves having a sugar tolerance test to see how the body copes with a known amount of sugar over a known period of time.

What causes insulin resistance?

Insulin resistance is more common in people who are obese, especially if they are carrying the excess fat around their waistline. Excess fat can get stuck inside the pancreas where is can cause problems with blood sugar control.

People from some ethnic backgrounds are more prone to metabolic syndrome. For example, those with a South Asian or black Afro-Caribbean background.

High blood pressure

Blood pressure is a measure of the force that your blood puts on your bloods vessels as it flows around the body. When your blood pressure is too high, your heart has to work harder to pump blood around the body, putting it under strain. This raises your risk of health problems.  

Blood pressure is recorded as two numbers, a top number and a bottom number:

  • systolic (the top number) - this is the pressure when your heart beats
  • diastolic (the bottom number) - this is the pressure when your heart is at rest in between the beats.

The numbers are written in millimetres of mercury, or mmHg. For example, a healthy blood pressure of 120 over 80 would be written as 120/80mmHg. Both numbers are important, but the top number is more important for diagnosing high blood pressure.

What is normal blood pressure?

Normal blood pressure is between 90/60mmHg and 120/80mmHg. 

If it's over 120/80mmHg but lower than 140/90mmHg this is pre-high blood pressure. It's not condsidered high, but it would be good to bring it down a bit. 

What is high blood pressure?

High blood pressure, or hypertension, is blood pressure constantly over 140/90mmHg. It's diagnosed when you have several readings, taken on at least three separate occasions, showing your systolic pressure is 140 or above, or your diastolic is 90 or above, or both.

If you have one high reading, that doesn't necessarily mean you have high blood pressure. That's because blood pressure is extremely variable. It can be raised by many things including stress, emotional state, physical activity and even “a visit to the doctors”. It's your blood pressure over the long term that's important. 

What causes high blood pressure? 

There isn't one single cause of high blood pressure. It's thought to be down to a combination of your genes, ethnic background, family history and your lifestyle. For example being overweight, lack of physical activity, smoking, eating foods high in salt and saturated fats and drinking alcohol can all raise your blood pressure. 

Why is high blood pressure (hypertension) dangerous?

High blood pressure which isn't brought under control raises the risk of heart attacks and stroke as well as kidney disease and eye damage.

If your blood pressure is too high your GP will talk to you about lifestyle changes and might prescribe medications to lower it. They will want to see you to check your blood pressure and medicines regularly.

Simple changes to your diet and lifestyle including eating less salt and exercising more can also make a huge difference and help to bring your blood pressure down. 

Getting a blood pressure check

It's impossible to know your numbers without having a blood pressure check, as you can't feel your blood pressure. Visit your GP, practice nurse of pharmacist to have your blood pressure checked. It's quick, free and painless. 


Obesity is the name used for someone who has gained enough excess weight to put their health at risk. Central obesity – where you carry excess fat around the waistline – can affect your blood fats and raise the risk of developing diabetes and metabolic syndrome.

How do you know if you're a healthy weight and shape?

Measuring your waistline is a good way of identifying your risk of illness. Use a flexible tape measure and wrap this around your waistline and see where you are in the chart below. For many people, the waistline is around the widest point – roughly around where your tummy button is. 

  Increased health risk Serious health risk
Women 80 cm (32 inches) or above 88 cm (35 inches) or above
Men 94 cm (37 inches) or above 102 cm (40 inches) or above
Asian men 90 com (36 inches) or above 101 cm (39 inches) or above

Too much fat in the blood

Doctors now recognise that there is a particular pattern of raised blood fats that put people at risk of metabolic syndrome and heart disease. They sometimes refer to this as dyslipidaemia.


The main type of fat that is higher than normal is triglyceride. These high levels of triglycerides often go hand in hand with low amounts of a kind of cholesterol called HDL cholesterol. Some doctors refer to this as “good cholesterol”.

Normal levels of these blood fats:

In the UK blood fats are measured in millimoles per litre (mmol/L). 

  • HDL cholesterol should be above 1mmol/L in men and 1.2mmol/L in women
  • Triglycerides should be below 1.7mmol/L (or less than 2.3mmol/L if you ate normally before the test)

What affects your blood fats?

Unhealthy patterns of blood fats happen when the body has more difficulty then normal coping with the fats and sugars in the food we eat. People with dyslipidaemia are often very overweight.