Understanding Diabetes

Diabetes Mellitus is a medical condition caused by an inability to use sugars due to the body producing ineffective insulin, an ineffective amount or clomplete lack of insulin in the body.   The effects can be life threatening.

Normal Physiology

Every cell in the human body needs sugars (as well as oxygen) as their source of energy.  The digestive system breaks down complex carbohydrates (long-chain molecules which are too large pass into cells) such as cellulose into simple (small-chain) carbohydrates such as glucose.

Cellulose to glucose 750.png

Glucose enters the blood stream where it is transported around the body to provide energy to cells, however, insulin is needed to combine with the glucose to enable it to pass into the cell.

Insulin is a hormone produced by endocrine glands on the pancreas; in a healthy person the body is able to regulate the amount of insulin produced, proportionate to the amount of glucose in the blood. 

Providing the cells have metabolised enough glucose, insulin also acts on the liver to stimulate enzymes which convert excess glucose to glycogen - a long-chain carbohydrate which can be stored for later use.

Given that all cells use glucose as energy, and all cells are constantly using this energy, blood glucose levels will always fall once the cells (and liver) have been 'topped up'.

When blood glucose levels begin to fall, the endochrine glands on the pancreas release another hormone, glucagon, which acts as the counter to insulin and breaks the stored glycogen back into glucose which can then be metabolised by cells.

These automatic responses to blood glucose levels (metabolising, storing, releasing and excreting)  maintains an optimum blood glucose level between 4 and 7 mmol/l ( or 80-120mg/dl in the US ).


A casualty with diabetes is either not producing enough insulin or their insulin is not effective - either way glucose circulating in their blood is not able to be metabolised by cells and can accumulate to dangerously high levels - hyperglycaemia.

Once the blood glucose level reach around 11.1mmol/l (or 200mg/dl US) the body attempts to excrete excess glucose through the urinary system, placing strain on the kidneys and requiring large amounts of water.

Types of Diabetes

Type 1 

  • Patients do not produce insulin; they require daily injections of synthesised insulin to metabolise glucose and control blood glucose levels.  Also known as Insulin Dependent Diabetes Mellitus (IDDM).
  • Type 1 patients are more likely to have metabolic problems, organ damage or nerve disorders.  
  • This type of diabetes was previously known as Early Onset Diabetes as it typically develops during childhood but can develop later in life.

Type 2

  • Patients produce inadequate amounts of insulin or their insulin is ineffective.
  • This condition usually appears later in life.
  • Many patients can be treated with diet, exercise and other non-insulin medications which stimulate the pancreas to produce more insulin. 
  • Type 2 diabetes was previously known as Non-Insulin Dependant Diabetes Mellitus (NIDDM) although this is not always true as some patients may also require supplemental insulin.


Without effective insulin or sufficient quantities, glucose builds up in the blood, unable to be metabolised by the cells which need it.

Without usable glucose, the body begins to metabolise other sources of energy - the most abundant being fat.  When fat is burned as an immediate fuel supply the byproducts are fatty acids and ketones, some of which are difficult for the body to excrete. 


You may have heard of ketones in regard to low-carb diets which force the body to burn fat as an immediate source of energy.  Some ketones (acetoacetate and ß-hydroxybutyrate) are used for energy; the heart muscle and kidneys, for example, prefer ketones to glucose.  Most cells, including the brain cells, are able to use ketones for at least part of their energy.  Acetone, however, is a ketone which is not used and so is excreted, giving a characteristic sweet smell on the person's breath or sweat.

An accumulation of ketones reduces the pH levels of the blood (acidosis) leading to Diabetic Ketoacidosis.

Ketoacidosis is a medical emergency; the signs and symptoms include a reduced level of consciousness, weakness, nausea, vomiting, abdominal pain, a weak and rapid pulse, and a distinctive deep and rapid breathing.

As the acidity increases, individual cells will cease to function.

If the casualty is not given correct fluids and insulin to reverse fat metabolism, ketoacidosis will lead to unconsciousness and death.

Ketoacidosis is more common in Type 1 diabetes because of the body's inability to produce any insulin.


In some situations, the diabetic casualty will have too low blood sugar.  This may be because:

  • They have taken too much of their Type 1 or Type 2 medication, metabolising too much glucose.
  • They have not eaten enough food.
  • They have been unusually active and have not planned for their energy demands.
  • They are cold or tired, increasing their energy demands.

A hypoglycaemic episode can occur much quicker than a hyperglycaemic event which typically can take days to develop.  Signs and symptoms include pale, clammy skin, breathing may be fast and weak, fast pulse, weakness or malaise and a reduced level of consciousness.  Typically the casualty will appear drunk, a stroppy drunk.

As the brain is starved of vital glucose, unconsciousness follows, then death.

The treatment is to give sugars - the simpler the better.  As quickly as the casualty deteriorated, the casualty will recover with simple sugars.

Is it Hyper or Hypoglycaemia?

One of the challenges in managing a casualty with diabetes is working out what is wrong with them; is their blood sugar level too high or too low?

  1. History
    Begin simply by asking the casualty what happened (or witnesses if the casualty is not conversant).Have they eaten recently, if so what?  Have they been particularly active or missed a meal?   A simple process of deduction will almost certainly reveal a correct diagnoses.
  2. Blood Glucose monitoring
    Casualties with known diabetes will measure their blood glucose levels several times a day using a blood glucose meter.  The blood glucose meter uses a sample of blood and measures the levels of glucose in millimoles per litre (mmol/l).  In the US it is measured in milligrams per decalitre (mg/dl).  In a normal state, everyone's blood glucose levels should be between 4 and 7 mmol/l or 80-120 mg/dl.A conscious and compliant casualty may be able to test themselves if you are able to bring them their measuring kit.
  3. Likelihood
    In reality, hypoglycaemia is far more common that hyperglycaemia. Everyone burns energy constantly so everyone is potentially susceptible to hypoglycaemia.Hypoglycaemia can occur very quickly.  Hyperglycaemia can take days to develop and as diabetics typically monitor their glucose levels several times a day, they are likely to catch glucose levels rising and medicate appropriately.  As such it is usually casualties who have not yet been diagnosed with diabetes who develop hyperglycaemia as they do not have the testing equipment or medication needed.
  4. Signs & Symptoms
    Unfortunately, the signs and symptoms of both hyper- and hypoglycaemia are similar; noticeably a reduced level of consciousness, weakness and a rapid pulse.  There are, however, some stark differences which may help confirm your suspicions from the previous evidence.

Signs & Symptoms

In an unconscious casualty, a casualty who is not conversant or where there is no history, it can be difficult to work out the situation from the four sources above.

While the signs and symptoms for both conditions are very similar, there are some important differences.


Signs & Symptoms












Missed or lost medication
High-sugar foods consumed
Excessive food consumed 


Excessive urination
Symptoms of dehydration 


Rapid and deep
Possible sweet odour 

Rapid, weak pulse
Warm, dry skin

  • If conscious and compliant, assist the casualty in measuring their blood glucose and medicating by gathering their equipment.
  • If they are not able to perform this task themselves, transfer to hospital.
  • This is a medical emergency requiring IV fluids and medication.
  • NEVER be tempted to administer insulin. You could easily kill someone


Missed meal
High activity levels
Too much medication




Normal to rapid

Rapid, weak pulse
Pale, clammy skin 

  • Some diabetics will have Glucogel® - a sugary gel in a bottle or tubes which can be swallowed or applied to the inside of the cheek.
  • Be aware of inserting your fingers into anyone's mouth!  Consider applying the jel using a tongue depressor, lollipop stick, guedel airway, a pen or anything else as long as it does not pose a choking hazard.
  • If the casualty is unconscious, prioritise ABC, position in the Safe Airway position and call 999.
  • If you are unsure of the condition - give sugar.
  • The hypoglycaemic casualty will recover rapidly but the amount of sugar given will have a negligible effect on the hyperglycaemic casualty1. 


First Aid Kits

You don't have to be diabetic to become hypoglycaemic; we all feel weak, tired and hungry when our blood sugar levels drop.

If you work with a known diabetic or work in an active, physically demanding job it may be worthwhile having sugar with you.  In fact, as hypoglycaemia is so common and easy to diagnose (by looking for a fast recovery once sugar is given), hypoglycaemia should be the first possibility to be checked for anyone with an altered mental status.


So should I have chocolate in my First Aid kit?

No.  It will get eaten.   By me, probably.

Look in any first aid kit, especially in the workplace an notice how many of them are incomplete because people will self treat and, despite their best intentions, they will not restock the kits.

Energy Gels.jpg

If it is known that there are chocolate bars in your first aid kits, they will get eaten by someone who has forgot their lunch, is on a late shift or is just bored.  And it will not be replaced.

Some diabetics will not carry Glucogel and we would not suggest every first aid kit is stocked with similar products 'just in case', largely because of the cost.

An ideal compromise is any energy gel; the type used by athletes.  Fast acting glucose which is ideally packaged for practical first aid kits.

And they taste awful, so are not likely to be eaten by a greedy guts.

1 Caroline, N. (2011). Emergence Care in the Streets. London: Jones and Bartlet. p629.

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