Diabetes, type 2 - Complications 

Complications caused by diabetes 

If diabetes is not treated, it can lead to a number of different health problems. High glucose levels can damage blood vessels, nerves and organs.

Even a mildly raised glucose level that does not cause any symptoms can have damaging effects in the long-term.

Heart disease and stroke

If you have diabetes, you are up to five times more likely to develop heart disease or have a stroke.

Prolonged, poorly controlled blood glucose levels increase the likelihood of atherosclerosis (a condition involving the furring and narrowing of your blood vessels).

This may result in a poor blood supply to your heart, causing angina (a dull, heavy or tight pain in the chest). It also increases the chance that a blood vessel in your heart or brain will become blocked, leading to a heart attack or stroke.

Nerve damage

High blood glucose levels can damage the tiny blood vessels in your nerves. This can cause a tingling or burning pain that spreads from your fingers and toes up through your limbs. It can also cause numbness which can lead to ulceration of the feet.

If the nerves in your digestive system are affected, you may experience nausea, vomiting, diarrhoea or constipation.


Retinopathy is where the retina (the light-sensitive layer of tissue) at the back of the eye is damaged. Blood vessels in the retina can become blocked or leaky, or can grow haphazardly. This prevents light from fully passing through to your retina. If it is not treated, it can damage your vision.

Annual eye checks are usually organised by a regional photographic unit. If significant damage is then detected, you may be referred to an ophthalmologist (a doctor who specialises in treating eye disease).

The better you control your blood sugar levels, the lower your risk of developing serious eye problems.

Diabetic retinopathy can be managed using laser treatment if it is caught early enough. However, this will only preserve the sight you have; it will not improve it.

Kidney disease

If the small blood vessels of your kidney become blocked and leaky, your kidneys will work less efficiently. It is usually associated with high blood pressure, and treating this is a key part of management.

In rare, severe cases, kidney disease can lead to kidney failure and a kidney replacement treatment with dialysis (or sometimes kidney transplantation) will be necessary.

Foot problems

Damage to the nerves of the foot can mean small nicks and cuts are not noticed and this, in combination with poor circulation, can lead to a foot ulcer developing. About 1 in 10 people with diabetes get a foot ulcer, which can cause serious infection.

If you have diabetes, look out for sores and cuts that do not heal, puffiness or swelling and skin that feels hot to the touch. You should also have a foot examination at least once a year.

If poor circulation or nerve damage is detected, check your feet every day and report any changes to your doctor, nurse or podiatrist (foot care specialist).

Read more about foot care and diabetes.

Sexual dysfunction

In men with diabetes, particularly smokers, nerve and blood vessel damage can lead to erection problems. This can usually be treated with medication.

Women with diabetes may experience:

  • a reduced sex drive
  • reduced pleasure from sex
  • vaginal dryness
  • a reduced ability to orgasm
  • pain during sex

If you experience a lack of vaginal lubrication, or you find sex painful, you can use a vaginal lubricant or a water-based gel.

Miscarriage and stillbirth

Pregnant women with diabetes have an increased risk of miscarriage and stillbirth. If your blood sugar level is not carefully controlled during the early stages of pregnancy, there is also an increased risk of the baby developing a birth defect.

Pregnant women with diabetes will usually have their antenatal check-ups in hospital or a diabetic clinic, ideally with an obstetrician (a doctor who specialises in pregnancy care).

This allows your care team to keep a close eye on your blood sugar levels and control your insulin dosage more easily, as well as monitoring the growth and development of your baby.

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Page last reviewed: 24/07/2012

Next review due: 24/07/2014


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The 2 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Bad_ass_crew1 said on 07 December 2013

I need help and advice I am type 2 and can't get an erection to fulfill a women.. So I now don't even try . We all need love in are lives but I have shut this emotion down.. Bit frustrating , I no when a women is interested and I feel inside that it's not worth trying as I have failed time and time again.. I am scared of using Viagra

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ljackson said on 20 July 2010

Can anyone help? My mum is diabetic and is currently on holiday where she has developed cellulitis, for which she's being treated with antibiotics. I'm concnerned that her odema and cellulitis could worsen on the flight home. Can she wear support stockings and mgiht they help?


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Looking after your eyes with diabetes

The NHS Diabetic Eye Screening Programme will arrange for you to have your eyes checked every year.

Everyone who is on a diabetes register will be given the opportunity to have a digital picture taken of the back of their eye. Speak to your GP to register.