The main symptoms of diabetes are:
feeling very thirsty
producing excessive amounts of urine
weight loss and muscle wasting (loss of muscle bulk)
Symptoms of type 1 diabetes can develop quickly, over weeks or even days. Other symptoms are:
itchiness around the vagina or penis or getting thrush regularly
blurred vision (caused by the lens of your eye becoming very dry)
Symptoms of hypoglycaemia (low blood glucose)
If you have diabetes, your blood glucose levels can become very low. This is known as hypoglycaemia (or a 'hypo'), and happens because any insulin in your body has moved too much glucose out of your bloodstream.
In most cases, hypoglycaemia occurs if you take too much insulin, although it can happen if you skip a meal, exercise very vigorously or drink alcohol on an empty stomach.
Symptoms of a 'hypo' include:
feeling shaky and irritable
nausea (feeling sick)
A hypo can be brought under control simply by eating or drinking something sugary.
If a hypo is not brought under control it can lead to confusion, slurred speech and unconsciousness. If this occurs, you will need to have an emergency injection of a hormone called glucagon. This hormone will raise the level of glucose in your blood.
Symptoms of hyperglycaemia (high blood glucose)
As diabetes occurs when the body cannot produce any, or enough, insulin to regulate your blood glucose, your blood glucose levels may become very high. This happens because there is no insulin to move glucose out of your bloodstream and into your cells to produce energy.
If your blood glucose levels become too high, you may experience hyperglycaemia. The symptoms are similar to the main symptoms of diabetes, but they may come on suddenly and severely. They include:
a dry mouth
a frequent need to pass urine
If left untreated, hyperglycaemia can lead to diabetic ketoacidosis, which can eventually cause unconsciousness and even death. Diabetic ketoacidosis occurs when your body begins to break down fats for energy instead of glucose, leading to a build-up of acids in your blood.
When to seek urgent medical attention
Seek urgent medical attention if you have diabetes and you develop:
a loss of appetite
nausea or vomiting (feeling or being sick)
a high temperature stomach pain
a fruity smell on your breath, which may smell like pear drops or nail varnish.