What Is High Blood Glucose
To fully understand your blood glucose levels, itâs important to know: a) what values are actually considered high, and b) factors that can cause your elevated reading in the first place.
High blood glucose, also known as hyperglycemia, occurs when there is too much sugar in the bloodstream. Low blood sugar, or hypoglycemia, is the result of too little glucose in the bloodstream. Hyperglycemia usually occurs because your body doesnât produce enough insulin or canât properly use the available insulin to remove the glucose from the bloodstream.
Using milligrams of glucose per deciliter of blood for measurement, high blood glucose readings after a meal indicating prediabetes can fall between 140 and 199 mg/dL. Levels reaching 200 mg/dL two hours after eating indicate you may already be insulin resistant or diabetic, though that diagnosis will need to come from your doctor. By comparison, the typical standard for normal glucose readings is to remain under 140 mg/dL throughout the day and under 100 mg/dL after eight hours of fasting.
A range of lifestyle factors, habits, and health conditions can cause high blood sugar. To debunk common hyperglycemia myths, review causes and symptoms, and discuss the best ways to address them, we spoke with two experts on high blood sugar levels: registered dietitian and For The Love of Diabetes creator Lori Zanini and registered dietitian nutritionist and diabetes management expert .
Monitor Blood Sugar Levels Closely
High blood sugar levels often do not cause symptoms until they run well over 200 mg/dL. As such, it is essential for a person with diabetes to monitor their blood sugar several times a day. Doing so will mean that blood sugar levels never get that high.
A person with diabetes can use a home glucose monitor to check blood sugar levels. These are available for purchase online.
Recommendations for how frequently to check glucose levels during the day will vary from person to person. A doctor can make the best recommendations regarding blood sugar monitoring to a person with diabetes.
Choose Low Glycemic Index Foods
The glycemic index measures and ranks various foods by how much they cause blood sugar levels to rise. Research shows that following a low glycemic index diet decreases fasting blood sugar levels.
Low glycemic index foods are those that score below 55 on the glycemic index. Examples of low glycemic foods include:
- sweet potatoes
- fruit
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How Can One Tell If I Have Diabetes By Examining My Blood
Your body converts sugar, also called glucose, into energy so your body can function. The sugar comes from the foods you eat and is released from storage from your bodys own tissues.
Insulin is a hormone made by the pancreas. Its job is to move glucose from the bloodstream into the cells of tissues. After you eat, the level of glucose in the blood rises sharply. The pancreas responds by releasing enough insulin to handle the increased level of glucose moving the glucose out of the blood and into cells. This helps return the blood glucose level to its former, lower level.
If a person has diabetes, two situations may cause the blood sugar to increase:
- The pancreas does not make enough insulin
- The insulin does not work properly
As a result of either of these situations, the blood sugar level remains high, a condition called hyperglycemia or diabetes mellitus. If left undiagnosed and untreated, the eyes, kidneys, nerves, heart, blood vessels and other organs can be damaged. Measuring your blood glucose levels allows you and your doctor to know if you have, or are at risk for, developing diabetes.
Much less commonly, the opposite can happen too. Too low a level of blood sugar, a condition called hypoglycemia, can be caused by the presence of too much insulin or by other hormone disorders or liver disease.
Prevent Type 2 Diabetes

If your test results show you have prediabetes, ask your doctor or nurse if there is a lifestyle change program offered through the CDC-led National Diabetes Prevention Program in your community. You can also search for an online or in-person program. Having prediabetes puts you at greater risk for developing type 2 diabetes, but participating in the program can lower your risk by as much as 58% .
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Can Drinking A Lot Of Water Lower Your Blood Sugar Levels
Although feeling very thirsty is a symptom of a hyper, drinking a lot of water will not bring your blood sugar levels down. It will only help to reduce your risk of dehydration.
Its important that you take your diabetes medication to bring your blood sugar levels down. If you have consistently high blood sugar levels, you will need to follow the advice below and speak to your diabetes healthcare team.
Avoiding High Blood Sugar And Dka
No matter how well they take care of themselves, people with diabetes will sometimes have high blood sugar levels. But the best way to avoid problems is to keep your blood sugar levels as close to your desired range as possible, which means following your diabetes management plan. Checking your blood sugar levels several times a day will let you know when your blood sugar level is high. Then you can treat it and help prevent DKA from happening.
High blood sugar levels don’t always cause symptoms, and a person who isn’t testing regularly might be having blood sugar levels high enough to damage the body without even realizing it. Doctors may use the HbA1c test to find out if someone has been having high blood sugar levels over time, even if the person has not had obvious symptoms.
Here are some other tips for avoiding high blood sugar levels and preventing DKA:
- Try to eat all your meals and snacks on time and not skip any.
- Take the right amount of insulin.
- Check your blood sugar levels regularly and your ketone levels when your diabetes management plan recommends it.
- Stick to your diabetes management plan.
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What If It Goes Untreated
Hyperglycemia can be a serious problem if you don’t treat it, so it’s important to treat as soon as you detect it. If you fail to treat hyperglycemia, a condition called ketoacidosis could occur. Ketoacidosis develops when your body doesn’t have enough insulin. Without insulin, your body can’t use glucose for fuel, so your body breaks down fats to use for energy.
When your body breaks down fats, waste products called ketones are produced. Your body cannot tolerate large amounts of ketones and will try to get rid of them through the urine. Unfortunately, the body cannot release all the ketones and they build up in your blood, which can lead to ketoacidosis.
Ketoacidosis is life-threatening and needs immediate treatment. Symptoms include:
- Shortness of breath
Talk to your doctor about how to handle this condition.
What Are The Symptoms Of Low Blood Sugar
- Confusion
- Difficulty speaking
- Muscle weakness
If you are experiencing an extremely low blood sugar, which is anything less than 40 mg/dL, that is not responding to fast-acting glucose or glucagon, and you have taken fast-acting insulin within the previous 2 hours, call 911 and seek immediate emergency medical attention.
This condition can be life-threatening if not treated.
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If My A1c Is Normal My Glucose Is Good
An A1C result thatâs below 5.7% is normal âs standards, but having a result below that number isnât the end of the story. Pregnancy, hemoglobin variants, anemia, liver disease, and certain medications can cause inaccurate A1C results.
Additionally, the A1C test is measuring your average glucose value over the past 3 months, but averages inherently do not capture highs and lows. So, you could have a normal average while also having abnormal glucose spikes. The A1C test should only supplement your regular blood sugar testing, not replace it completely.
What Else Can I Do To Help Manage My Blood Sugar Levels
Eating a healthy diet with plenty of fruit and vegetables, maintaining a healthy weight, and getting regular physical activity can all help. Other tips include:
- Keep track of your blood sugar levels to see what makes them go up or down.
- Eat at regular times, and dont skip meals.
- Choose foods lower in calories, saturated fat, trans fat, sugar, and salt.
- Track your food, drink, and physical activity.
- Drink water instead of juice or soda.
- Limit alcoholic drinks.
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What Levels Of Blood Sugar Are Dangerous
If you live with diabetes, you probably know that life with the condition is similar to walking on a tightrope.
Staying in range without too many high and low blood sugars is a constant balancing act.
But what levels of blood sugar are actually considered dangerous?
This article will explore the issue and provide advice for how you can help manage both the highs and lows of diabetes, literally!
Youre Developing Blisters Dryness Or Other Skin Changes

Small pieces of extra skin, called skin tags, may form in the creases of skin, especially if you have diabetes and youre trying to find ways to manage your weight, notes the ADA. Dark, thick areas of soft skin may form on the back of the neck or hands, armpits, face, or other areas. These can be a sign of insulin resistance, Zanini says. Blisters, infections, dryness, itchiness, discolorations, and abnormalities of the skin can all be warning signs of high blood sugar. Check with your doctor if these skin changes develop.
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Who Is At Risk For High Blood Sugar
Dr. Curry-Winchell says, “Anyone can be at risk for high blood sugar. If you have a family history of diabetes considered uncontrolled by diet or medication, taking a medication such as steroids situational or emotional stress, infections, low physical activity, diet high in fat/carbohydrates.”6254a4d1642c605c54bf1cab17d50f1e
Fasting Plasma Glucose Test
A fasting plasma glucose test is taken after at least eight hours of fasting and is therefore usually taken in the morning.
The NICE guidelines regard a fasting plasma glucose result of 5.5 to 6.9 mmol/l as putting someone at higher risk of developing type 2 diabetes, particularly when accompanied by other risk factors for type 2 diabetes.
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The Danger Of Low Blood Sugar
Low blood sugar, also known as hypoglycemia, can become a lot more dangerous more quickly. Hypoglycemia, if left untreated, can quickly result in diabetic coma and death.
Low blood sugars will not lead to permanent complications in most cases but cause frequent, short-term complications in the form of being physically unable to function when experiencing a low. They require fast-acting glucose as treatment.
Symptoms of low blood sugar can hit different people at different times, and some people may not feel their low blood sugars at all , which can be very dangerous.
Continuous glucose monitoring systems and diabetes alert dogs can help people detect their lows earlier, before they become extremely dangerous.
Hypo unawareness occurs in about 40% of people with type 1 diabetes, and less frequently in people with type 2 diabetes.
Additionally, one study showed that the average person with type 1 diabetes experiences two episodes of low blood sugar per week!
Low blood sugars can happen for many reasons, all of which result from too much insulin in the bloodstream and not enough glucose for the body to function properly.
Reasons can be anything from taking too much insulin for food, to accidentally over-bolusing with an insulin pump, to not finishing a meal, to drinking alcohol in excess, or even after physical exertion and exercise while not reducing basal insulin settings appropriately.
Diagnosing High Blood Sugar
The easiest way to detect high blood sugar is by having your blood drawn as part of your annual physical examination. Part of what they’re measuring is your fasting blood glucose level. It’s important that the test be done while fasting, the American Diabetes Association says, because it’s a good indicator of your normal level of glucose without the influence of exercise or food 1. The normal range for fasting blood glucose is 70 to 125 mg/dl. If your values are higher than 130 mg/dl, your doctor may ask you to repeat the test in a week. **If your results are high during the second test, an oral glucose tolerance test will likely be ordered.
During an OGTT, the patient is asked to drink a high concentration of glucose in liquid. Blood samples are drawn in the beginning and at 2-hour intervals throughout the day to determine how well the body processes glucose. If the glucose concentrations remain high, you may have diabetes. Another way to test for hyperglycemia is to measure your hemoglobin A1c . Blood glucose competes with oxygen by attaching itself to the hemoglobin in the red blood cells, according to the Mayo Clinic. High concentrations of HbA1c can interfere with the way that cells get oxygen from the blood.
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What Blood Sugar Level Is Prediabetic
Exercise, Fitness & Nutrition Expert | Lark Health
Prediabetes is a condition with increased blood sugar, but how is it measured? Exactly what sugar level range is considered prediabetic, and how is that different from diabetes? Here is what you need to know about blood sugar levels in prediabetes, and what you can do about yours.
If you have been told that you have prediabetes, or you think that you might have it or be at risk for it, you can take your awareness in a positive way. While nobody actually wants to think about having a chronic health condition, being aware of prediabetes can be seen as a fork in the road of life.
On one branch of the fork in the road, prediabetes can lead to type 2 diabetes. Most people who get prediabetes take this branch, and end up with diabetes. However, you can choose to take the other branch in the road because in most cases, prediabetes is reversible.
Are you at risk for type 2 diabetes? Lark Diabetes Prevention Program is a personalized program to help you lower your risk by making healthy lifestyle changes, such as losing weight and increasing physical activity. Your personal Lark coach is available to support you 24/7 on your smartphone. Lark can help you make small changes that fit into your lifestyle and have big results for your health!
What Is Considered Low Blood Sugar
For the average person with diabetes, low blood sugar means anything under 80 mg/dL .
Very low blood sugars are any readings under 40 mg/dL. Anything under 40 mg/dL is considered extremely dangerous and potentially fatal.
A person is at a significantly higher risk of falling into a diabetic coma if they cannot get their blood sugar above 40 mg/dL for several hours.
If a person is experiencing a severe low, and they are unable to chew food or swallow liquids, they will require an emergency shot of Glucagon .
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Urgent Advice: Call Your Care Team Immediately Or Get Help From Nhs 111 If:
You think you have high blood sugar and:
- you’re feeling sick, being sick or have stomach pain
- you’re breathing more quickly than usual or your heart is beating faster than usual
- you feel drowsy or are struggling to stay awake
- your breath has a fruity smell
- you feel confused or have difficulty concentrating
- you have a high level of ketones in your blood or pee
These could be signs you’re becoming seriously unwell.
You can call 111 or get help from 111 online.
Page last reviewed: 26 May 2022 Next review due: 26 May 2025
Causes Related To Diet

Processed foods and sugar
Diet and how it relates to blood glucose values can vary immensely from person to person. But, research suggests that eating processed foods can increase blood glucose.
Overeating or grazing
Itâs a common belief that snacking throughout the day will keep blood glucose levels steady. But, a 2013 study found that eating two large meals per day helped reduce blood glucose more effectively than six small meals per day. Itâs also important to keep our meals to the right proportions, as overeating can raise blood glucose levels as well.
Dehydration
Some research has found a connection between low water intake and a greater risk of hyperglycemia. This is most likely because less water in the body means the concentration of glucose in the blood is higher.
Vitamin and mineral deficiencies
Research into this cause is ongoing. Yet, studies suggest diets lacking micronutrients like chromium, magnesium, or vitamin D may contribute to high blood glucose.
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High Blood Sugar Level Causes
Several types of diabetes and medical conditions are the primary cause of high blood sugar levels. Most of which are unpreventable issues but are the reason for a spike in high blood sugar. The causes for high blood sugar levels are as follows:
Causes of low blood sugar levels are very different and are as important to be aware of, as they are in fact easier to control.
Talk With Your Healthcare Provider
If you think you’ve been doing all you can to keep your blood sugar in control, but your readings are still high, it may be time to switch medications, if you are taking them. Diabetes is a progressive disease, and over time, the beta cells in the pancreas that produce insulin can stop making the hormone altogether.
Ultimately, your healthcare provider will look at the full picture and do additional testing to find out if there is a bigger problem.
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