Diabetes - At a glance

Diabetes mellitus:

  • Is characterised by high levels of glucoseA simple sugar that is an important source of energy in the body., the sugar used as fuel by the body, in the bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid.
  • Is also associated with glucoseA simple sugar that is an important source of energy in the body. in the urine
  • May be caused by a lack of the hormoneA substance produced by a gland in one part of the body and carried by the blood to the organs or tissues where it has an effect. insulinA hormone produced by the beta cells of the pancreas that acts to lower blood glucose levels., or failure of the body to respond to insulinA hormone produced by the beta cells of the pancreas that acts to lower blood glucose levels.. Insulin is a hormoneA substance produced by a gland in one part of the body and carried by the blood to the organs or tissues where it has an effect. produced by the pancreas that normally acts to lower glucoseA simple sugar that is an important source of energy in the body. levels in the bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid., for example by converting glucoseA simple sugar that is an important source of energy in the body. into fatOne of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body.
  • Has two main forms, type 1 and type 2 diabetes mellitusDisordered energy metabolism and high levels of glucose in the blood owing to a lack of insulin, or poor response of the body to insulin.
  • Type 1 is caused by a reduction in insulinA hormone produced by the beta cells of the pancreas that acts to lower blood glucose levels. levels, while type 2 is caused by the resistanceThe ability of a microbe, such as a type of bacteria, to resist the effects of antibiotics or other drugs. of the body to the actions of insulinA hormone produced by the beta cells of the pancreas that acts to lower blood glucose levels.
  • Other possible causes of diabetes mellitusDisordered energy metabolism and high levels of glucose in the blood owing to a lack of insulin, or poor response of the body to insulin. include pregnancy (gestational diabetesAny level of glucose intolerance first detected during pregnancy.), disease of the pancreas, and some medications, like steroids.

For convenience, diabetes mellitusDisordered energy metabolism and high levels of glucose in the blood owing to a lack of insulin, or poor response of the body to insulin. will be referred to simply as 'diabetes' from here on.

Risk factors and prevention

Having family members with either type 1 or type 2 diabetes increases a person's risk for getting diabetes as well.

Additional risk factors for type 1 diabetes are less clear, but may include:

  • Childhood exposure to some bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. and other microorganismsOrganisms that are too small to be seen with the naked eye, such as bacteria and viruses.
  • Dietary factors.

As well as family history, important risk factors for type 2 diabetes include:

  • Obesity
  • Physical inactivity
  • Increasing age
  • Being of South Asian, African, African-Caribbean and Middle Eastern descent.

It is difficult to take steps to prevent type 1 diabetes, since many of the risk factors involved have an effect early in life.

Steps to prevent the onset of type 2 diabetes include:

  • Healthy eating patterns
  • Leading an active lifestyle
  • For some, taking medications like orlistat or metformin.

More detail on risk factors

More detail on prevention

Symptoms and signs

 
The symptoms of diabetes are all related to the high levels of sugar, or glucoseA simple sugar that is an important source of energy in the body., in the bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid., as well as the presence of glucoseA simple sugar that is an important source of energy in the body. in the urine. These symptoms include:
  • Increased thirst
  • A need to urinate often
  • Tiredness
  • Muscle wasting
  • Weight loss
  • Increased risk of infectionInvasion by organisms that may be harmful, for example bacteria or parasites., such as thrush
  • Blurred vision
  • Increased hunger.
Muscle wasting and weight loss are more often seen in type 1 diabetes. In fact, because bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. glucoseA simple sugar that is an important source of energy in the body. levels rise more slowly in type 2 diabetes, sometimes people with this condition do not notice any symptoms at all.
 
Poor glucoseA simple sugar that is an important source of energy in the body. control may result in the conditions of diabetic ketoacidosisCondition mainly found in type 1 diabetes, in which high levels of ketones are present; these are acidic compounds produced by fat breakdown. in type 1 diabetes, or hyperosmolar hyperglycaemiaAlso known as hyperosmolar non-ketotic state - a state of having very high levels of glucose in the blood, most commonly associated with type 2 diabetes. in type 2 diabetes. Both may be brought on by illness or by incorrect medication dosing, and may result in a reduced consciousness level if left untreated.

More detail on symptoms and signs

Tests and diagnosis

Blood tests for diabetes include:

  • Blood glucoseA simple sugar that is an important source of energy in the body.
  • Oral glucose toleranceThe ability of the body to maintain a normal glucose level following the ingestion of glucose. test. This involves fasting overnight before drinking a glucoseA simple sugar that is an important source of energy in the body. solution. Blood glucoseA simple sugar that is an important source of energy in the body. is checked before and two hours after drinking the solution, to assess the body's response to it.
  • Glycated haemoglobin, or HbA1cAn abbreviation for glycated haemoglobin, a measure of how well glucose levels have been controlled over the previous three months or so in a person with diabetes. It is expressed as a percentage.. This gives an indication of how well glucoseA simple sugar that is an important source of energy in the body. has been controlled over a period of months.
  • Urine tests for diabetes include checks for glucoseA simple sugar that is an important source of energy in the body., ketonesA group of compounds that are produced by fat metabolism. and protein.

More detail on tests and diagnosis

Choosing treatments

Treatment of diabetes may involve:

  • Lifestyle changes, including diet and exercise
  • Insulin (for type 1 diabetes, or advanced type 2 diabetes)
  • Other antidiabetic medications (for type 2 diabetes), such as metformin, sulphonylureas, alpha-glucosidase inhibitors, thiazolidinediones and incretinA type of hormone produced in the gut, which stimulates insulin release. therapy
  • Surgery - transplantation of the whole pancreas, or the part of the pancreas that produces insulinA hormone produced by the beta cells of the pancreas that acts to lower blood glucose levels., the pancreaticRelating to the pancreas. islets.

Additional care for people with diabetes may include:

  • Blood pressure control
  • Lipid-lowering medication
  • Pneumococcal and influenzaA viral infection affecting the respiratory system. vaccinations.

More detail about treatments

The future

Complications

Poor glucoseA simple sugar that is an important source of energy in the body. control may lead to a number of other health problems further down the line. These may include:

  • Cardiovascular disease including heart disease and stroke
  • Eye problems, nerveBundle of fibres that carries information in the form of electrical impulses. problems and kidney failure.
  • Close control of bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. glucoseA simple sugar that is an important source of energy in the body. levels can delay or even prevent the development of these complications.

More detail on complications of diabetes

Living with diabetes

Self-monitoring of bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. glucoseA simple sugar that is an important source of energy in the body. levels may give a better understanding of how exercise, diet and medication impact diabetes control

Annual check-ups are important to detect any early signs of complications, and should include an assessment of the eyes, kidneys, nervous system and feet, as well as looking for any signs of heart disease.

Because diabetes is a chronicA disease of long duration generally involving slow changes. condition that needs ongoing care, stressRelating to injury or concern. management techniques may help.

More detail on life with diabetes