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Hyperglycaemia (High Blood Sugars)

People with diabetes are advised to keep their blood glucose levels within acceptable limits (usually 4-10mmol/l). If you manage to keep your glucose (sugar) levels acceptable, you reduce the risk of developing short and long term complications.

What is Hyperglycaemia?
Ideally blood sugar levels should be kept between 4 and 7 mmol/l. but occasionally it is bound to go higher than that.

Worrying hyperglycaemia means a high blood sugar (glucose) level which is above 15 mmol/L. An occasional high blood glucose reading shouldn't cause too much concern. Regularly high blood glucose levels can lead to increased chances of long term diabetes complications. When the glucose is very high it can cause short term problems such as feeling thirsty, passing a lot of water, blurred vision, dehydration and even coma in certain circumstances. A level of more than 20 is of real concern and you should always take action and seek advice. If you have very high sugar levels and start vomiting you should report urgently for medical advice.

What are the symptoms?
During the early stages of hyperglycaemia there may be no symptoms. Even so, you should take action to correct the problem and not wait until you feel unwell. The following symptoms may develop: tiredness, increased thirst, increased urination, weakness and blurred vision. Vomiting, dehydration and confusion are serious signs.

What can cause Hyperglycaemia?
Please find below a list of the most common causes-

  • Eating too much,

  • The wrong types of food,

  • Not enough insulin or diabetes tablets,

  • Missing treatment

  • Not using your insulin equipment correctly.

  • Any illness, especially infection, can also cause the sugar to rise quickly.

How to treat Hyperglycaemia?
Continue with your diabetes treatment. Never miss your insulin if your sugar is high. Even if you cannot eat, take your insulin and have a liquid meal such as lucozade, milk, fruit juice, soup. Drink plenty of water. Test your blood glucose levels every 2-4 hours to see if things settle. Consult your G.P or Diabetes Specialist team as soon as possible. If you get vomiting or drowsiness, dial 999 immediately or ask someone to make the call on your behalf.

How to prevent Hyperglycaemia?
Stick to a sensible balanced diet and keep active. Ensure you know how to use your equipment (insulin pen, glucose monitoring meters etc) correctly. Stick to a steady treatment pattern. Take your medication as agreed with your medical team.

Seeking advice and what care to expect
Seek advice if you have high blood sugars, especially if you are uncertain how to deal with them. Your medical team will assess the situation and will teach you how to respond if the sugar levels are high including how to adjust your insulin. They will show you how to correctly use any equipment you should require for your diabetes treatment. They will teach you the rules to follow if you are ill. Please also read the leaflet on "Illness and sick day rules".