Diabetes, when poorly controlled, results in multiple complications. Diabetes is a leading cause of kidney failure, blindness, limb amputation, heart attack and stroke. Diabetes complications can be broadly divided into those affecting the small blood vessels (microvascular) and those affecting the large blood vessels (macrovascular).

Microvascular (small blood vessels) complications of diabetes

Macrovascular (large blood vessels) complications of diabetes

Eye (Blindness)Heart (Heart Attacks)
Kidney (Kidney Failure)Brain (Strokes)
Nerve (Amputations)Limbs (Amputations)

3 microvascular complications of diabetes

How diabetes can affect your​ eyes

Diabetes eye disease (diabetic retinopathy) results from reduced blood flow to the light sensing nerve layer of the eye (retina).

“Over time, there is formation of fragile and leaky new blood vessels and nerve layer swelling. These changes can progress to blindness if not identified early and treated,” says Dr Suresh Rama Chandran, Associate Consultant, Department of Endocrinology at Singapore General Hospital, a member of the SingHealth​ group.

How to protect your eyes when you have diabetes

Early diabetes-related changes to the eye may not cause any symptoms. Hence, it is important to have your eye checked annually even if you have no eye symptoms, in order to pick up these ​changes early and prevent blindne​ss.

However, if you develop a gradual blurring of vision or hazy vision, please see your doctor immediately. In some patients, blood vessels leak at the part of the retina responsible for central vision, causing loss of vision.​

Eye checks can be done by taking a photo of the back of your eye, a process known as fundus photography at the Diabetes and Metabolism Centre​ (DMC). This photo is reported by the Singapore National Eye Centre​ (SNEC). If further consultation with an eye specialist is required, you will be referred to an eye specialist at SNEC.

How diabetes can affect your kidneys

Diabetes kidney disease (diabetic nephropathy) starts with protein (albumin) leak in the urine. At this stage, the patient with diabetes may not have any symptoms due to kidney disease. However, this early stage can be identified easily by doing a urine test.

Protein leak in the urine is the earliest sign of diabetes kidney disease and if left untreated, it can progress to kidney failure, eventually requiring dialysis.

How to protect your kidneys when you have diabetes

Urinary protein leak improves with improvement in glucose and blood pressure. Certain blood pressure medications (ACEI/ARB) are also used to reduce urinary protein leak and retard further progression of diabetes kidney disease. If you are found to have urinary protein leak, these medications will be recommended even if your blood pressure is normal.

How diabetes can affect your nerves

Diabetes nerve disease (diabetic neuropathy) most commonly affects the nerves of the upper and lower limbs. It can also affect nerves that control the eye and nerves of the face and head. Most common symptoms experienced is tingling, burning, and pricking sensation or numbness of the hands and feet. If diabetes is poorly controlled the nerve disease gets worse and spreads to involve larger regions of the limbs.

Many patients are unaware of their reduced ability to sense pain and touch. This puts them at risk of injuries to their limbs that go unnoticed (e.g. burns from walking barefoot on hot surface, injury from stepping on a sharp object). These wounds are exposed to contamination from the environment and get infected. If not identified early and treated, infection spreads deeper to involve the muscle and bone eventually requiring amputations.

What to do to protect your fe​et when you have diabetes

Hence it is important to check your feet regularly for any injuries, wounds, blisters and skin thickening (callus). You should also attend an annual diabetic foot screening with​ your health provider to check for any reduced sensation and blood flow to your feet.

S​ee next page for diabetes complications affecting the heart, brain, and limbs and tips to prevent them​.

Ref: O17