If glucose is high what does that mean

Blood glucose that gets too high or too low can be dangerous. To stay safe and healthy, check your blood glucose regularly and watch for certain symptoms, like being very hungry, tired or sleepy. If your blood glucose is outside the normal range, take the steps described below to start feeling better.

Table of Contents Show

High Blood Glucose: Hyperglycemia
High Blood Glucose: Diabetic Ketoacidosis (DKA)
Low Blood Glucose: Hypoglycemia
Early signs and symptoms
Later signs and symptoms
When to see a doctor
From Mayo Clinic to your inbox
Risk factors
Complications
Long-term complications
Emergency complications
What can cause blood glucose to be high?
What happens when glucose level is high?
What is considered a high glucose level?

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. Sometimes, the medications you take for other problems cause high blood glucose.

Symptoms of hyperglycemia include:

Being very thirsty
Being very tired
Having blurry vision
Having to urinate often

If you have these symptoms, check your blood glucose right away. If it’s too high, follow these steps:

Check your blood glucose every four hours. If your level does not go down after two checks or your symptoms get worse, call a member of your diabetes team.
Drink water or other sugar-free liquids, such as diet soda or Crystal Light.
You may need to take an extra dose of insulin. Your diabetes educator talks with you more about this.

High Blood Glucose: Diabetic Ketoacidosis (DKA)

If your insulin level is too low, your blood glucose could become so high that it is unsafe. You might develop a serious problem called diabetic ketoacidosis (or DKA). This usually happens in people with Type 1 diabetes and those with glucose levels over 500.

If you have DKA, chemicals called ketones start to make a lot of acid in your body. The acid and high blood glucose can make you very sick. You might also become dehydrated (lose body fluid). You can prevent DKA by carefully giving yourself the correct insulin dose every day.

If you have any of the following symptoms of DKA, get to your local emergency department right away. You need to be treated with insulin and fluids that are given to you through an IV (a thin tube placed in your arm):

Blurry vision
Decreased appetite
Dry mouth, eyes or skin
Fast breathing
Feeling confused or irritable
Feeling very weak or tired
Fruity-smelling breath
Stomach pain, nausea or vomiting

Low Blood Glucose: Hypoglycemia

Hypoglycemia can occur when blood glucose drops below normal levels or drops too quickly. Your blood glucose level is too low if it is under 70 mg/dL.

Hypoglycemia can be caused by:

A combination of these factors
Being more active than usual
Drinking alcohol
Eating at the wrong time for the medications you take
Skipping or not finishing meals or snacks
Taking too much diabetes medication

You can have hypoglycemia without any symptoms. That makes it important to check your blood glucose levels regularly. When hypoglycemia does cause symptoms, they can include:

Being sweaty
Fast heartbeat
Feeling irritable
Feeling shaky
Feeling tired
Headache
Hunger

If you have these symptoms, check your blood glucose right away. If it is too low (under 70 mg/dL), take something with sugar right away. This quickly raises your blood glucose level. Some good options include:

Five to six hard candies
One-half cup (4 oz) of fruit juice or regular soda
Three glucose tablets

You should also check your blood glucose again after 15 minutes. If it’s still low, again take something with sugar. Check your blood glucose level again after another 15 minutes. If it is still low, call a member of your diabetes team. If your next meal is more than an hour away, eat a small snack.

*The content on this website is for informational purposes only and is not medical advice. Please consult a physician regarding your specific medical condition, diagnosis and/or treatment.

Overview

High blood sugar, also called hyperglycemia, affects people who have diabetes. Several factors can play a role in hyperglycemia in people with diabetes. They include food and physical activity, illness, and medications not related to diabetes. Skipping doses or not taking enough insulin or other medication to lower blood sugar also can lead to hyperglycemia.

It's important to treat hyperglycemia. If it's not treated, hyperglycemia can become severe and cause serious health problems that require emergency care, including a diabetic coma. Hyperglycemia that lasts, even if it's not severe, can lead to health problems that affect the eyes, kidneys, nerves and heart.

Symptoms

Hyperglycemia usually doesn't cause symptoms until blood sugar (glucose) levels are high — above 180 to 200 milligrams per deciliter (mg/dL), or 10 to 11.1 millimoles per liter (mmol/L).

Symptoms of hyperglycemia develop slowly over several days or weeks. The longer blood sugar levels stay high, the more serious symptoms may become. But some people who've had type 2 diabetes for a long time may not show any symptoms despite high blood sugar levels.

Early signs and symptoms

Recognizing early symptoms of hyperglycemia can help identify and treat it right away. Watch for:

Frequent urination
Increased thirst
Blurred vision
Feeling weak or unusually tired

Later signs and symptoms

If hyperglycemia isn't treated, it can cause toxic acids, called ketones, to build up in the blood and urine. This condition is called ketoacidosis. Symptoms include:

Fruity-smelling breath
Dry mouth
Abdominal pain
Nausea and vomiting
Shortness of breath
Confusion
Loss of consciousness

When to see a doctor

Seek immediate help from your care provider or call 911 if:

You have ongoing diarrhea or vomiting, and you can't keep any food or fluids down
Your blood glucose levels stay above 240 mg/dL (13.3 mmol/L) and you have symptoms of ketones in your urine

Make an appointment with your health care provider if:

You have ongoing diarrhea or vomiting, but you're able to take some foods or drinks
You have a fever that lasts more than 24 hours
Your blood sugar levels stay above 240 mg/dL (13.3 mmol/L) despite treatment, and you have symptoms of ketoacidosis
You have trouble keeping your blood glucose within your target range

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Causes

During digestion, the body breaks down carbohydrates from foods — such as bread, rice and pasta — into sugar molecules. One of the sugar molecules is called glucose. It's one of the body's main energy sources. Glucose is absorbed and goes directly into your bloodstream after you eat, but it can't enter the cells of most of the body's tissues without the help of insulin. Insulin is a hormone made by the pancreas.

When the glucose level in the blood rises, the pancreas releases insulin. The insulin unlocks the cells so that glucose can enter. This provides the fuel the cells need to work properly. Extra glucose is stored in the liver and muscles.

This process lowers the amount of glucose in the bloodstream and prevents it from reaching dangerously high levels. As the blood sugar level returns to normal, so does the amount of insulin the pancreas makes.

Diabetes drastically reduces insulin's effects on the body. This may be because your pancreas is unable to produce insulin, as in type 1 diabetes. Or it may be because your body is resistant to the effects of insulin, or it doesn't make enough insulin to keep a normal glucose level, as in type 2 diabetes.

In people who have diabetes, glucose tends to build up in the bloodstream. This condition is called hyperglycemia. It may reach dangerously high levels if it is not treated properly. Insulin and other drugs are used to lower blood sugar levels.

Risk factors

Many factors can contribute to hyperglycemia, including:

Not using enough insulin or other diabetes medication
Not injecting insulin properly or using expired insulin
Not following your diabetes eating plan
Being inactive
Having an illness or infection
Using certain medications, such as steroids or immunosuppressants
Being injured or having surgery
Experiencing emotional stress, such as family problems or workplace issues

Illness or stress can trigger hyperglycemia. That's because hormones your body makes to fight illness or stress can also cause blood sugar to rise. You may need to take extra diabetes medication to keep blood glucose in your target range during illness or stress.

Complications

Long-term complications

Keeping blood sugar in a healthy range can help prevent many diabetes-related complications. Long-term complications of hyperglycemia that isn't treated include:

Cardiovascular disease
Nerve damage (neuropathy)
Kidney damage (diabetic nephropathy) or kidney failure
Damage to the blood vessels of the retina (diabetic retinopathy) that could lead to blindness
Feet problems caused by damaged nerves or poor blood flow that can lead to serious skin infections, ulcerations and, in some severe cases, amputation
Bone and joint problems
Teeth and gum infections

Emergency complications

If blood sugar rises very high or if high blood sugar levels are not treated, it can lead to two serious conditions.

Diabetic ketoacidosis. This condition develops when you don't have enough insulin in your body. When this happens, glucose can't enter your cells for energy. Your blood sugar level rises, and your body begins to break down fat for energy.
When fat is broken down for energy in the body, it produces toxic acids called ketones. Ketones accumulate in the blood and eventually spill into the urine. If it isn't treated, diabetic ketoacidosis can lead to a diabetic coma that can be life-threatening.
Hyperosmolar hyperglycemic state. This condition occurs when the body makes insulin, but the insulin doesn't work properly. Blood glucose levels may become very high — greater than 600 mg/dL (33.3 mmol/L) without ketoacidosis. If you develop this condition, your body can't use either glucose or fat for energy.
Glucose then goes into the urine, causing increased urination. If it isn't treated, diabetic hyperosmolar hyperglycemic state can lead to life-threatening dehydration and coma. It's very important to get medical care for it right away.

Prevention

To help keep your blood sugar within a healthy range:

Follow your diabetes meal plan. If you take insulin or oral diabetes medication, be consistent about the amount and timing of your meals and snacks. The food you eat must be in balance with the insulin working in your body.
Monitor your blood sugar. Depending on your treatment plan, you may check and record your blood sugar level several times a week or several times a day. Careful monitoring is the only way to make sure that your blood sugar level stays within your target range. Note when your glucose readings are above or below your target range.
Carefully follow your health care provider's directions for how to take your medication.
Adjust your medication if you change your physical activity. The adjustment depends on blood sugar test results and on the type and length of the activity. If you have questions about this, talk to your health care provider.

Aug. 20, 2022

What can cause blood glucose to be high?

What causes high blood sugar?.

stress..

an illness, such as a cold..

eating too much, such as snacking between meals..

a lack of exercise..

dehydration..

missing a dose of your diabetes medication, or taking an incorrect dose..

over-treating an episode of hypoglycaemia (low blood sugar).

What happens when glucose level is high?

Having too much sugar in the blood for long periods of time can cause serious health problems if it's not treated. Hyperglycemia can damage the vessels that supply blood to vital organs, which can increase the risk of heart disease and stroke, kidney disease, vision problems, and nerve problems.

What is considered a high glucose level?

Fasting blood sugar test. 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.