Type 1 diabetes causes the body stops making insulin, while type 2 diabetes results in the body either not making enough insulin or cells in the body stop responding to it.
Around 4.5 million people are now estimated to have diabetes in the UK, one million of them are undiagnosed.
Type 1 diabetes is an auto-immune disease, the pancreas stops producing insulin because antibodies produced by the immune system attack cells in the organ because they mistake them for foreign invaders. Scientists don't understand what triggers this type of diabetes, but some believe a viral infection may be one of the causes.
Although type 1 diabetes does run in families, 90 per cent of people who develop it will have no family history of the disease.
Type 2 diabetes accounts for about 90 per cent of diabetes cases worldwide and is caused by a combination of lifestyle factors (although certain ethnic groups are at higher risk), including diet, being over weight and low activity
Needing to pass urine frequently, increased thirst, fatigue and unintended weight loss are all symptoms of type 1 and type 2 diabetes.
Symptoms of type 2 diabetes can develop very slowly and might not be obvious straight away. The type 1 disease comes on much quicker and will make you feel generally unwell, making it more likely to be diagnosed at an early stage.
Other symptoms to look out for include: wounds that fail to heal normally, genital itching, skin infections, blurred vision and cramping.
Doctors can diagnose type 1 and type 2 diabetes with a glycated haemoglobin blood test (known as a HbA1C test).HbA1C is a molecule found in the blood; the more glucose in the blood, the more HbA1C will be found.
Who gets it?
Type 1 was once referred to as 'juvenile diabetes' because children are the most commonly diagnosed age group, but this is now regarded as out-dated as in fact it can develop at any age.
Around 90 per cent of peoplewith type 2 diabetes are either overweight or obese. Other risk factors include having a waist of over 37 inches (94 cm) for black and white men, and 31.5inches (80 cm) for all women, and 35 inches (89cm) or more in Asian men. Other risk factors include: being over 40 years old, having a parent or sibling with type 2 diabetes, or having polycystic ovary syndrome, a condition which can cause high blood sugar levels.
Type 1 diabetes is treated with insulin injections or an insulin pump which delivers insulin in small amounts throughout the day.
Type 2 diabetes can in some case be managed by diet and lifestyle changes, including losing weight (if your body mass index is too high), eating a healthier diet comprising of more fruit and vegetables as well as less fat and sugar, and taking more exercise.
Recent research has found significant weight loss can not only treat type 2 diabetes but reverse it. For those newly diagnosed, a 600-calorie a day diet for a period of 8 weeks can be enough to reverse the disease, although this is not yet standard medical advice.
If your blood sugar levels remain too high or increase you may need pills to bring it down. Metformin is a commonly prescribed pill which works by making your body more sensitive to insulin, helping you use it more efficiently. Other drugs include sulphonylureas, pioglitazones and gliptins.
Chromium and cinnamon are supplements found to be helpful in managing blood sugar, but always inform your GP if you are taking them, as they can, if taken with medication lower your blood sugar too much.
Your GP should monitor your blood sugar levels regularly with a HbA1C blood test, at least twice a year, but more often if your blood sugar levels are under control.