A reading above 300 mg/dL can be dangerous, according to the University of Michigan, which recommends immediately informing your doctor if you have two or more readings of 300 mg/dL in a row. In severe cases, very high blood sugar levels (well above 300 mg/dL) can result in coma.
Mild high blood sugar
If your blood sugar levels are consistently higher than your target range (usually 11 mmol/L to 20 mmol/L, and 11 mmol/L to 14 mmol/L in children), you may have mild symptoms of high blood sugar. You may urinate more than usual if you are drinking plenty of liquids.
If your blood sugar level is slightly high for a short time, emergency treatment won't be necessary. But if it continues to rise you may need to act fast to avoid developing diabetic ketoacidosis (DKA). If your blood sugar level is 15 mmol/l or more, you should check your blood or urine for ketones.
If HbA1c is more than 48 mmol/mol or fasting blood glucose is more than 11 mmol/L, your blood sugar is high. For most people without diabetes, normal blood sugar levels are: between 4 and to 6 mmol/L before meals. less than 8 mmol/L two hours after eating.
Target blood sugar levels differ for everyone, but generally speaking: if you monitor yourself at home – a normal target is 4-7mmol/l before eating and under 8.5-9mmol/l two hours after a meal. if you're tested every few months – a normal target is below 48mmol/mol (or 6.5% on the older measurement scale)
A fasting blood sugar level less than 100 mg/dL (5.6 mmol/L) is normal. A fasting blood sugar level from 100 to 125 mg/dL (5.6 to 6.9 mmol/L) is considered prediabetes. If it's 126 mg/dL (7 mmol/L) or higher on two separate tests, you have diabetes.
From 90 to 130 mg/dL (5.0 to 7.2 mmol/L) for adults. From 90 to 130 mg/dL (5.0 to 7.2 mmol/L) for children, 13 to 19 years old. From 90 to 180 mg/dL (5.0 to 10.0 mmol/L) for children, 6 to 12 years old. From 100 to 180 mg/dL (5.5 to 10.0 mmol/L) for children under 6 years old.
Call 000 or go to the hospital emergency department if: you cannot keep any food or fluids down. your blood glucose level stays above 15mmol/L and you have ketones. your symptoms are getting worse and you are unable to manage your condition yourself.
If you have diabetes, you'll need to check your blood sugar, also called glucose, to know if it's too high, too low, or meets your goal. A diabetic coma could happen when your blood sugar gets too high -- 600 milligrams per deciliter (mg/dL) or more -- causing you to become very dehydrated.
250 mg/dL (13.9 mmol/L) or higher.
This is a caution zone — your blood sugar may be too high to exercise safely. Before exercising, test your urine for ketones — substances made when your body breaks down fat for energy.
Why Skipping Meals Is Harmful to Diabetes. Skipping meals isn't the best diet plan for anyone, but for people with diabetes, skipping a meal can lead to immediately dangerous blood sugar swings, as well as potential complications down the road.
Emergency treatment for severe hyperglycemia
If you have signs and symptoms of diabetic ketoacidosis or hyperosmolar hyperglycemic state, you may be treated in the emergency room or admitted to the hospital.
Drink plenty of water
Drinking plenty of water helps your kidneys flush out excess sugar. One study found that people who drink more water lower their risk for developing high blood sugar levels. And remember, water is the best. Sugary drinks elevate blood sugar by raising it even more.
When people eat food the food breaks down into sugars which is only stored with the help of insulin. if insulin is not produced adequately then it is stored in the blood stream rising a person's blood glucose levels.
If you don't eat, your blood sugar levels are lower and medication may drop them even more, which can lead to hypoglycemia. Hypoglycemia can cause you to feel shaky, pass out, or even go into a coma.
The dawn phenomenon leads to high levels of blood sugar, a condition called hyperglycemia. It usually happens between 4 a.m. and 8 a.m.
Hyperglycemia, the term for expressing high blood sugar, has been defined by the World Health Organisation as: Blood glucose levels greater than 7.0 mmol/L (126 mg/dl) when fasting. Blood glucose levels greater than 11.0 mmol/L (200 mg/dl) 2 hours after meals.
Extreme thirst. Lightheadedness. Flushed, hot, dry skin. Restlessness, drowsiness, or difficulty waking up.
48 mmol/mol or over (6.5% if you're given a percentage) Test done by a health professional after not eating for a few hours (fasting glucose test) Over 7 mmol/L.
Diabetic shock is a state of severe low blood sugar, known as hypoglycemia. Diabetic shock is an emergency and can lead to a diabetic coma without treatment. Hypoglycemia can sometimes happen rapidly and may even occur when a person follows their diabetes treatment plan.
However, at very blood glucose levels (typically above 33 mmol/L) a dangerous condition called Hyperosmolar Hyperglycaemic State (HHS) can develop. Periods of illness or lack of sufficient diabetes medication could lead to development of Hyperosmolar Hyperglycaemic State.
A measurement of over 11mmol/L is usually considered a diagnosis of hyperglycaemia if the measurement is taken at any time or 7mmol/L if the test is done fasting. Consistently high measurements of blood glucose will mean you have diabetes (diabetes mellitis).