Diabetes — The Facts

What is Diabetes?

Definition — Diabetes mellitus is a chronic condition characterised by high levels of sugar (glucose) in the blood.

Diabetes affects how the body controls and uses glucose, and people with diabetes have chronic high blood glucose levels (hyperglycaemia).

The inability to produce insulin, or by the body not being able to use insulin effectively.

Diabetes can lead to dangerous difficulties. People with diabetes have a greater risk of microvascular issues.

A recent World Health Organisation (WHO) report determined there were 171 million people in the world with diabetes in the year 2000 and this is forecasted to increase to 366 million by 2030.


The terms ‘type 1’ and ‘type 2’ are used to divide diabetes with some subgroups such as LADA and monogenic diabetes.

Diabetes can be classified into the following general categories:

10% of diagnosed cases

A chronic autoimmune disease that develops when the immune system destroys the insulin-producing cells of the pancreas. People with type 1 diabetes require insulin replacement every day. Type 1 usually develops during youth, but it can also develop in adulthood.

80% of diagnosed cases

Usually caused by lifestyle factors and is often preventable by keeping a healthy lifestyle. Type 2 diabetes happens when the body becomes resistant to insulin and/or the body does not produce adequate insulin.

10% of diagnosed cases

Raised blood glucose levels occurring for the first time during pregnancy, usually in the second or third trimester. Gestational diabetes often happens after birth, however, it can increase the risk of diabetes in later life for both the mother and the child.

Diabetes Globally

The prevalence of diabetes is steadily rising. In most high-income countries, it is one of the highest cause of death, and the epidemic is rapidly growing in developing countries.

  • Globally, one in 11 adults has diabetes
  • In 2015, five million people died of diabetes (one every six seconds)
  • Three-quarters of people with diabetes live in low and middle-income countries
  • 12% of the world’s total health spending is on diabetes.

The prevalence of diabetes mellitus is higher in the elderly and in certain countries. All forms of diabetes predispose to developing complications that are both microvascular and macrovascular.

The increased mortality and morbidity linked with diabetes are largely due to these vascular complications.

The chances for people diagnosed with diabetes mellitus has increased greatly since the mid-1980s. This is due to a better understanding of diabetes by doctors, nurses, dietitian and, most of all, patients themselves. The widespread introduction of blood glucose self-monitoring has greatly increased the ability of motivated people to manage their diabetes and raise both their metabolism and quality of life.

Common Symptoms

Hunger and fatigue: Lack of insulin or resistance to insulin means glucose can’t be used effectively by the body, causing hunger and tiredness. Insulin aids the transport of glucose from the blood to muscles; insufficient or ineffective insulin leaves the muscles without an energy source and thus a feeling of tiredness ensues. Hunger is triggered by the body seeking extra energy sources but unfortunately eating more without the aid of insulin to transport the food to the muscles just escalates the blood glucose level.

Urinating more and being thirsty: The body will pass more fluid to attempt to excrete glucose and reduce blood glucose levels. This, in turn, increases thirst, then fluid consumption increases, which further increases urination.

Dry mouth and itchy skin: An effect of dehydration from excessive urination.

Blurred vision: Many people experience blurred vision in the early stages of diabetes. This blurred vision is caused by fluid seeping into the lens of the eye and causing the lens to swell, changing its shape and altering its ability to focus properly. Once diabetes treatment begins and blood glucose is under control, the lens resumes its normal shape and vision improves.

Yeast infections: Yeast feeds on glucose. Infections can grow in folds of skin including between fingers and toes, under breasts and around sex organs.

Slow-healing cuts and sores: High blood sugar affects blood flow and also the haemoglobin’s ability to carry oxygen. Over time diabetes causes damage to the nerves that also impedes wound healing.

Pain and numbness in feet and legs: Caused by nerve damage.

Unexplained weight loss: When the body is unable to extract energy from food, it will instead break down muscle and fat.

Nausea and vomiting: A byproduct of fat breakdown is ketones. When fat is broken down to access an alternate energy source, the ketones released into the blood can become toxic and cause ketoacidosis.

Diabetic ketoacidosis occurs in unstable type 1 diabetes and can be fatal if not treated. Nausea is a symptom of diabetic ketoacidosis.

  • a fasting glucose test (8-hour fast)
  • random glucose test
  • oral glucose tolerance test (OGTT) where a fasting patient has a blood test then drinks a sugary drink and has a blood test at one and two hours later.
  • an HbA1c test
  • an autoantibody test.

A positive test result, without high blood sugar, should be repeated on a different day to confirm the diagnosis. The glycated haemoglobin (HbA1c blood test) is also being used to diagnose diabetes due to its convenience.



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