If blood sugar levels fall or rise abnormally in someone with diabetes, they’ll experience a variety of symptoms.

Hypoglycaemia
Hypoglycaemia is when the blood sugar levels fall below normal. Glycaemia measures is the level of sugar in blood.

Hypoglycaemia may occur:
- after an insulin injection
- after taking oral diabetes medication
- if a meal is missed or delayed
- after strenuous exercise
- if alcohol is drunk on an empty stomach

The symptoms of hypoglycaemia vary from person to person. Mild hypoglycaemia may cause:
- weakness
- dizziness
- sweating
- hunger
- shaking
- irritability
- mood swings

A mild hypoglycaemia can usually be treated with some form of sugar. Types of sugar to use during mild crisis :
- dextrose tablets (carry these if you have diabetes)
- three sugar lumps
- two teaspoons of sugar
- chocolate or sweet biscuits
- a sweet drink

When the blood glucose level falls even lower, then the person may behave strangely and become confused (often mistakenly interpreted as drunkenness). Under these circumstances it may be easier and quicker to give sugar in liquid form, such as a sweet drink.

In severe hypoglycaemia, the person loses consciousness. Under these circumstances an injection of glucagon is given, which temporarily raises the level of blood glucose. Once the person is conscious they can be given some sugar and a snack to prevent the hypo from recurring.

Always have sugar tablets or another form of sugar available

People with diabetes and those close to them are taught to look out for signs that their sugar level may be low, and are advised to always have sugar tablets or another form of sugar available to raise the level quickly. This solves the problem quickly and prevents serious consequences.

People with diabetes are advised to carry some form of identification saying that they have diabetes, so that people will realise their condition should they get into difficulty and need help.

Hyperglycaemia
Hyperglycaemia is when the blood glucose level is too high. When it’s mildly raised then symptoms of uncontrolled diabetes occur, namely excessive thirst, passing urine frequently, tiredness, weakness and lethargy.
If the blood glucose level becomes dangerously high then the person becomes dehydrated and may become comatose. This is a medical emergency that requires hospital treatment.

What Is Blood Sugar?
Your blood sugar level, or blood glucose level, refers to the concentration of sugar (in the form of glucose) in your blood. The unit of measurement is millimoles per liter (mmol/L).

Why is there sugar in the blood?
Every time you eat food, your body has the task of breaking that food down into a useable form of energy it can use to keep you functioning properly. All foods are (generally) made up of carbohydrates, proteins, fats, vitamins, minerals, fiber and water. Carbohydrate rich foods give your body its main form of energy. They get broken down into glucose and move into the bloodstream where they are absorbed by cells for use or storage. Glucose, or “blood sugar”, is likened to “the gasoline that is essential to make your car run”.

Why would i need to manage my sugar blood levels?
Your body needs a constant supply of carbohydrates during the day and you should be aware of your blood carbohydrates levels.
During the day there are two types of problems that can occur that are carbohydrate related.
a) your blood does not have enough carbohydrate during the day : your body will start break down the fat that you have stored to produce carbohydrate. This is done at the expense of releasing toxins which are not good for you. This is also tapping in your body mass and the fat stored in your muscles.
b) you blood has too much carbohydrate : Probably after a big meal or you’ve eaten too much sweets. Your blood now has too much sugar which risks to harm your body, so Insulin is released in your blood to bring down sugars to an acceptable level. Producing insulin is a tiring experience and during this time you will feel sluggish.

Why Blood Sugar Levels Change During The Day
Your blood sugar levels vary during the day/night. The direction it varies (up or down) is due to a number of factors such as those listed below:
1. Eating food :  As the carbs in food break down, glucose is released into the bloodstream ready to be absorbed by cells. Increased glucose in the bloodstream = higher blood sugar level.
2. Exercise : Exercise provides many benefits to your body, including burning excess sugar and reducing insulin resistance (by making cells more receptive to insulin, so rather than requiring more insulin to facilitate glucose uptake, the insulin you already have becomes a bit more effective). However the effect on blood sugar depends on the type of exercise, the duration of exercise, glucose and insulin levels before you start exercising.
During long, intense workouts the body may release adrenaline which counteracts the efforts of insulin. The normal process for blood sugar would be to be absorbed by cells (via insulin) for utilization or storage. Adrenaline causes the glucose to be redirected to where it is required for use immediately rather than for storage. Read more here.
3. Your physiology : The fitter you are the better. More specifically, if you have a greater muscle to fat ratio, you will burn energy at a faster rate and therefore be more effective at reducing your blood glucose level. Also, muscles do not rely on insulin to absorb/use blood glucose – same goes for the brain.
(My sister gave me this great analogy – imagine a small muscle and a large muscle contracting at the same time. Which one would use/burn more energy to contract? The big one, simply because it is a bigger muscle!)
4. Emotions : Stress increases your blood glucose level. It also causes some people to forget to take their medication, turn to comfort foods, overeat and therefore introduce a higher than normal amount of glucose in the blood.
5. Sleeping : People often talk about “dawn phenomenon” with regard to diabetes, where your blood sugar level spikes in the mornings as a result of the body releasing hormones which increase insulin resistance (perhaps). The cause of this is unknown. However, another explanation could be a slow metabolism of dinner from the night before. Some research also suggests that not getting enough sleep causes the liver to produce/release more glucose, hence increasing your blood sugar levels.
6. Medications : Obviously, the medication you take regulates your blood sugar level and therefore your readings during the day, depending on when you took the medication.