Having either type 1 or type 2 diabetes can put you at increased risk of developing several other health problems. These diabetic complications are mainly caused by the long-term effects of raised blood sugar levels on blood vessels and nerves, and develop over many years.
Our animation shows how diabetes complications can affect your body. However, keep in mind that tight control of blood glucose levels (along with control of other risk factors, such as high blood pressure and raised cholesterol) can help prevent these complications from developing, and slow their progression if they do develop.
Having diabetes can increase your risk of having a stroke. This is because increased blood glucose levels can contribute to the development of atherosclerosis (hardening and narrowing of the arteries), which can lead to a stroke when it affects the arteries that supply blood to your brain.
High blood sugar levels can damage the blood vessels that supply your retina (the light-sensitive part of the eye that relays images to your brain), resulting in a condition called diabetic retinopathy.
Diabetes can also increase your risk of developing cataracts (clouding of the lens within your eye) and glaucoma (increased fluid pressure within the eyeball).
These conditions can cause blurred or reduced vision, as well as loss of eyesight if left untreated.
Raised blood sugar levels can promote atherosclerosis (hardening and narrowing of the arteries). When atherosclerosis affects the arteries that supply blood to your heart, it can cause coronary heart disease, leading to heart attacks and angina.
People with diabetes also often have other risk factors for heart disease, such as high blood pressure and obesity. Plus, diabetes is often associated with high levels of cholesterol and triglycerides (types of fat in the blood), further increasing the risk of heart disease.
4. Blood pressure
People with diabetes have an increased risk of developing high blood pressure. This may be related to the damaging effects of high blood sugar levels on the blood vessels.
Diabetes can also damage the nerves that normally control and adjust your blood pressure. One consequence of this is that your blood pressure may drop dramatically when you stand up, making you feel suddenly light-headed or even faint. This is called postural hypotension.
5. Gastrointestinal system
Diabetes can damage the nerves that control some automatic bodily functions, including digestion. Some of the symptoms that may result from this nerve damage (autonomic neuropathy) include indigestion, bloating, nausea, vomiting, diarrhoea and constipation.
Prolonged high blood sugar levels can damage the filtering units and blood vessels in your kidneys, allowing protein to leak out into your urine. Over time, this makes your kidneys less efficient at filtering out waste products from the blood. This condition is known as diabetic nephropathy, and can progress to kidney failure requiring dialysis or a kidney transplant.
Controlling blood sugar levels and blood pressure can help prevent and slow the progression of kidney disease.
People with diabetes are also at increased risk of developing kidney infections.
High blood glucose levels can result in autonomic neuropathy — damage to the nerves that control automatic bodily functions. When the nerves supplying the bladder are involved, this can result in problems with bladder control and difficulty emptying the bladder completely, leaving a person prone to developing bladder infections.
8. Reproductive organs
Men with diabetes are at increased risk of erectile dysfunction (impotence). This is because consistently high blood sugar levels can damage nerves and contribute to blood vessel narrowing, disrupting the nerve and blood supply to the penis that is necessary for an erection.
Women with diabetes can have problems with sexual response and vaginal lubrication due to nerve damage.
High blood glucose levels can damage the blood vessels and nerves that supply your legs and feet. The poor blood supply that results from damage to the arteries (known as peripheral vascular disease) can cause leg pain and cramps when walking, and in severe cases, gangrene of the toes and feet.
The nerve damage — known as peripheral neuropathy — can also cause pain in the legs and feet, but more often causes numbness and tingling.
People with diabetes are prone to developing serious foot problems, including non-healing ulcers. This is mainly due to nerve and blood vessel damage. Numb feet caused by nerve damage make injuries more likely because you cannot feel pain or changes in pressure or temperature. Also, injuries to joints or bones may go unnoticed, sometimes resulting in foot deformities.
Poor circulation means that sores and ulcers often take longer to heal, and infection is more likely. In extreme cases, infected foot ulcers that are not healing require amputation.
Remember, tight control of blood glucose levels and a healthy lifestyle can go a long way to helping prevent these complications and slowing their progression. Also, regular check-ups with your doctor are essential, because many complications do not cause symptoms in their early stages when they are easier to treat.