High blood sugar levels can seriously damage parts of your body, including your feet and your eyes. These are called the complications of diabetes. But you can take action to prevent or delay many of these problems.

What are the complications of diabetes?

You might hear your healthcare team talk about two types of diabetes complications: serious ones that build up over time called chronic complications and ones that can happen at any time called acute complications.

Chronic complications

These are long-term problems that can develop gradually, and can lead to serious damage if they go unchecked and untreated.

Eye problems (retinopathy)

Some people with diabetes develop an eye disease called diabetic retinopathy which can affect their eyesight. If retinopathy is picked up – usually from an eye screening test - it can be treated and sight loss prevented.

Foot problems

Having diabetes means that you’re more at risk of serious foot problems and which can lead to amputation if untreated. Nerve damage can affect the feeling in your feet and raised blood sugar can damage the circulation, making it slower for sores and cuts to heal. That’s why it’s important to tell your GP if you notice any change in how your feet look or feel.

Heart attack and stroke

When you have diabetes, high blood sugar for a period of time can damage your blood vessels. This can sometimes lead to heart attacks and strokes.

Kidney problems (nephropathy)

Diabetes can cause damage to your kidneys over a long period of time making it harder to clear extra fluid and waste from your body. This is caused by high blood sugar levels and high blood pressure. It is known as diabetic nephropathy or kidney disease.

Nerve damage (neuropathy)

Some people with diabetes may develop nerve damage caused over time by high blood sugar levels. This can make it harder for the nerves to carry messages between the brain and every part of our body so it can affect how we see, hear, feel and move.

Gum disease and other mouth problems

Too much sugar in your blood can lead to more sugar in your saliva. This brings bacteria which produces acid which attacks your tooth enamel and damages your gums. The blood vessels in your gums can also become damaged, making gums more likely to get infected.

Related conditions, like cancer

If you have diabetes, you’re more at risk of developing certain cancers. And some cancer treatments can affect your diabetes and make it harder to control your blood sugar.

Sexual problems in women

Damage to blood vessels and nerves can restrict the amount of blood flowing to your sexual organs so you can lose some sensation. If you have high blood sugar, you are also more likely to get thrush or a urinary tract infection.

Sexual problems in men

The amount of blood flowing to your sexual organs can be restricted which may cause you to have difficulty getting aroused. It may lead to erectile dysfunction, sometimes called impotence.

Acute complications 

These can happen at any time and may lead to chronic complications.

• Hypos – when your blood sugars are too low
• Hypers– when your blood sugars are too high
• Hyperosmolar Hyperglycaemic State (HHS) – a life-threatening emergency that only happens in people with type 2 diabetes. It’s brought on by severe dehydration and very high blood sugars.
• Diabetic ketoacidosis (DKA) – a life-threatening emergency where the lack of insulin and high blood sugars leads to a build-up of ketones.

What causes diabetes complications?

High sugar levels in your blood over a long period of time can seriously damage your blood vessels. If your blood vessels aren’t working properly, blood can’t travel to the parts of your body it needs to. This means your nerves won’t work properly either and means you lose feeling in parts of your body. Once you’ve damaged the blood vessels and nerves in one part of your body, you’re more likely to develop similar problems in other parts of your body. So if your feet are damaged, serious heart problems can follow.

We know that the higher your HbA1c level, the more you’re at risk of developing complications. Even a slightly high HbA1c increases your risk.

But it’s not just about blood sugars. High blood pressure, smoking and a lot of fat in your blood (cholesterol) can all damage your blood vessels and put you even more at risk.

How do I prevent or delay complications?

They’re not inevitable. Keeping blood sugar, blood pressure and blood fats under control will hugely help to reduce your risk of developing complications. This means going to your diabetes health checks and finding out from your diabetes healthcare team how to look after yourself between appointments.You can prevent or delay the complications of diabetes. But you need to take action and it’s all about managing your diabetes well.

Stopping smoking and lowering your HbA1c levels, blood fats and blood pressure will prevent or slow down these complications. Giving up smoking is the best thing you can do if you have diabetes because smoking makes it even harder for blood to flow around your body.

Keeping a close eye on these levels and understanding your numbers will help you take control of your health. We know it’s not always as simple as that, but we’re here to help.

If you have chronic complications

When you have one chronic complication, you’re much more at risk of developing other complications. So if your blood vessels are damaged in your feet for example, the damage can happen to other parts of your body like your kidneys and heart too. This means you need to stay on top of your health checks and blood sugar levels when you’re managing other problems