First, the numbers. “Post-meal blood sugars of 140 mg/dl [milligrams per deciliter] and higher, and fasting blood sugars over 100 mg/dl [can] cause permanent organ damage and cause diabetes to progress,” Ruhl writes.
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.
High Blood Glucose: Hyperglycemia
Hyperglycemia means that you have too much blood glucose. It happens when your blood glucose level is around 200 mg/dL or higher. Hyperglycemia can happen if you miss taking your diabetes medications, eat too much or do not get enough exercise.
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.
Drinking water regularly may rehydrate the blood, lower blood sugar levels, and reduce diabetes risk ( 20 , 21 ). Keep in mind that water and other zero-calorie drinks are best. Avoid sugar-sweetened options, as these can raise blood glucose, drive weight gain, and increase diabetes risk ( 22 , 23 ).
In general: Less than 140 mg/dL (7.8 mmol/L ) is normal. 140 to 199 mg/dL (7.8 to 11.0 mmol/L ) is consistent with prediabetes. 200 mg/dL (11.1 mmol/L ) or higher after two hours suggests diabetes.
Both low and high blood-sugar levels lead to serious health consequences. High blood sugar may cause nausea, vomiting, or shortness of breath, while low blood sugar may cause confusion, dizziness, blurred vision, seizures, unconsciousness, or even death, McDermott explains.
Persistently high blood sugar usually means you have diabetes. 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.
The dawn phenomenon is an early-morning rise in blood sugar, also called blood glucose, in people with diabetes. 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.
What should your blood sugar be when you wake up? Whenever possible, aim to keep your glucose levels in range between 70 and 130 mg/dL in the morning before you eat breakfast, and between 70 and 180 mg/dL at other times.
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.
On average, blood sugar readings were lower when people put pressure on the finger. The finding, according to the researchers, is in line with advice to avoid firm squeezing of the tested finger.
The average U.S. adult drinks about two 8-ounce (240-milliliter) cups of coffee a day, which can contain around 280 milligrams of caffeine. For most young, healthy adults, caffeine doesn't appear to noticeably affect blood sugar (glucose) levels, and having up to 400 milligrams a day appears to be safe.
The dawn phenomenon
In the early hours of the morning, hormones, including cortisol and growth hormone, signal the liver to boost the production of glucose, which provides energy that helps you wake up. This triggers beta cells in the pancreas to release insulin in order to keep blood glucose levels in check.
The A1C test measures your average blood sugar level over the past 2 or 3 months. An A1C below 5.7% is normal, between 5.7 and 6.4% indicates you have prediabetes, and 6.5% or higher indicates you have diabetes.
Prediabetes means you have a higher than normal blood sugar level. It's not high enough to be considered type 2 diabetes yet. But without lifestyle changes, adults and children with prediabetes are at high risk to develop type 2 diabetes.
It's common. And most importantly, it's reversible. You can prevent or delay prediabetes from turning into type 2 diabetes with simple, proven lifestyle changes.
So people reduce their carb intake, go on a low carbohydrate diet, and focus on eating healthy fats and (in many cases) too much protein. But what this solution crucially fails to address is insulin resistance, which is the true cause of those high blood glucose numbers.
Look out for these surprising triggers that can send your blood sugar soaring: Sunburn—the pain causes stress, and stress increases blood sugar levels. Artificial sweeteners—more research is needed, but some studies show they can raise blood sugar. Coffee—even without sweetener.
While there are myths that state those with diabetes should not consume dairy, these products, including cheese, can actually be beneficial when consumed in moderate amounts. Cheese, in particular, can actually be great at helping to manage blood sugar levels because of its low glycemic index.
Some facilities test the first drop of blood. Others require nursing personnel to wipe away the first drop of blood with gauze, and test the second drop. The rationale for wiping away the first drop of blood is that the alcohol in the prep pad, and consequently on the fingertip, may alter values.
Recommended finger: the World Health Organisation recommends the middle or ring fingers are used for blood glucose tests (second and third fingers). You may want to avoid using your little finger due to the skin being thin.
Testing is usually recommended before meals and at bedtime if you're taking multiple daily injections. You may need to test only before breakfast and sometimes before dinner or at bedtime if you use just an intermediate- or a long-acting insulin.
Exercise is a fast and effective way to lower your blood sugar levels. Exercise can lower your blood sugar for 24 hours or more after you've finished. This is because it makes your body more sensitive to insulin. Physical activity causes the body to demand glucose for energy.
Barley or jau water is high in insoluble fibre, which makes it good for diabetics. It is recommended for diabetics as it helps stabilise blood glucose levels. Make sure you drink unsweetened barley water to get effective results. The antioxidant properties of barley water also helps keep many diseases at bay.