Diabetes Mellitus

The term diabetes mellitus (diabetes) refers to a group of disorders which result in high blood glucose (blood “sugar”) levels. Blood glucose levels are regulated in the body by a number of hormones, the most important of which is insulin, which is produced by the pancreas. The cause of high blood glucose differs according to the type of diabetes.

Symptoms of high blood glucose levels include:

  • Thirst, drinking a lot and urinating excessively
  • Weight loss
  • Lethargy and fatigue
  • Blurred vision
  • Infections, such as thrush or skin infections
  • Dizziness, headache, nausea

The complications of diabetes mellitus are similar regardless of the cause or type of diabetes and result from chronic exposure to high blood glucose levels. Complications include damage to the eyes, kidneys, nerves, and blood vessels. The risk of complications of diabetes can be minimised by maintaining optimal levels of blood glucose. Regular monitoring for diabetes complications is essential in all individuals with these conditions.


Type 1 diabetes

Type 1 diabetes occurs due to a deficiency in insulin production by the pancreas.  This is most commonly due to an autoimmune cause, where the body produces antibodies to the insulin-producing cells in the pancreas, leading to the destruction of these cells and resultant insulin deficiency.  

Type 2 diabetes

Type 2 diabetes is the most common form of diabetes. Type 2 diabetes generally results from resistance of the body’s tissues to the effect of insulin, with consequent high blood glucose levels. 

Other forms of diabetes

There are other forms of diabetes which cannot be easily categorised as type 1 or type 2 diabetes including Gestational diabetes/ Diabetes of pregnancy.

Genetic forms of diabetes

Genetic forms of diabetes are rare but important to recognised. There are a number of directly inherited forms of diabetes, such as Maturity Onset of the Young (MODY) and mitochondrial diabetes (MIDD) which occur as a result of specific genetic variations, which are directly passed from parent to child through DNA.