Table of ContentsView AllTable of ContentsTypesSymptomsCausesDiagnosisTreatmentPrognosisCoping
Table of ContentsView All
View All
Table of Contents
Types
Symptoms
Causes
Diagnosis
Treatment
Prognosis
Coping
Low blood sugar (glucose) levels, called hypoglycemia, can cause fatigue or even fainting. Hypoglycemia is more common for individuals withdiabetesand may result from too much medication, not eating enough, or overexercising.
The opposite effect,hyperglycemia(high blood sugar levels), happens during times of stress or poorly-controlled diabetes. If left untreated, hyperglycemia damages organs throughout the body.
Insulin helps to transform the food you eat into energy that your body can use. If your body doesn’t produce insulin or becomes resistant to insulin’s effects, you may experience blood sugar issues.
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Hyperglycemia and Hypoglycemia Types
The pancreas maintains the flow of glucose between your bloodstream and your cells. In diabetes, the flow is out of balance, either not producing insulin (type 1 diabetes) or not responding to insulin (type 2 diabetes).
Type 1 diabetes is an autoimmune disease usually diagnosed early in life, while type 2 diabetes takes time to develop. The early stage of type 2 diabetes is called prediabetes.
Gestational DiabetesType 2 diabetes symptoms may show up during pregnancy, which is a condition called gestational diabetes. Gestational diabetes usually goes away after giving birth but indicates a higher diabetes risk in the future.
Gestational Diabetes
Type 2 diabetes symptoms may show up during pregnancy, which is a condition called gestational diabetes. Gestational diabetes usually goes away after giving birth but indicates a higher diabetes risk in the future.
Early symptoms of hyperglycemia may go unnoticed, especially in the case of type 2 diabetes. However, in type 1 diabetes, blood sugar elevations can quickly turn into a dangerous condition calledketoacidosis.
Low blood sugar can also become a life-threatening situation for people with diabetes. Here’s what you can expect in high and low blood sugar episodes.
Hyperglycemia
Early symptoms of hyperglycemia include:
Hyperglycemia may leave you feeling weak and tired. Slow-healing cuts and sores, vaginal or skin infections, and weight loss can also be attributed to chronically elevated blood sugar levels.
Ketoacidosis SymptomsKetoacidosis may cause:Deep labored breathing or hyperventilationDehydrationRapid heartbeatUnusual fruity smell on the breath (acetone breath)Vomiting
Ketoacidosis Symptoms
Ketoacidosis may cause:Deep labored breathing or hyperventilationDehydrationRapid heartbeatUnusual fruity smell on the breath (acetone breath)Vomiting
Ketoacidosis may cause:
Hypoglycemia
Hypoglycemia symptoms can start out minimal and develop rapidly into a health crisis. Symptoms of hypoglycemia may vary but are most dangerous for individuals with type 1 and type 2 diabetes.
Hypoglycemia may cause:
Can Low Blood Sugar Cause High Blood Pressure?
Causes vary for hyperglycemia and hypoglycemia.
The body may be overproducing insulin. As a result, the cells become desensitized to it, meaning it’s unable to do its job of bringing high blood sugars down.
Blood sugar goes up after a meal, especially if that meal contains simple carbohydrates. Sugary beverages are particularly prone to spiking blood sugars since there’s no fiber, fat, or protein to slow digestion.
Once sugar is broken down and released into the bloodstream, insulin is released to push it into the cells for quick energy or storage. When insulin isn’t working well, blood sugar stays high in the blood until it’s eventually filtered out through the kidneys.
Other causes ofhyperglycemiainclude:
Just as eating too many carbohydrates can cause blood sugars to rise, eating too few carbohydrates or skipping and delaying meals (especially after taking insulin or medications) can cause low blood sugars.
Intense physical activity can also cause hypoglycemia as your muscles use sugar from the blood to fuel exercise. Further, alcohol disrupts the balance of blood sugar and may mask the early symptoms leading to hypoglycemia.
Hyperglycemia can be detected in a fasting state or after a meal.
Fasting blood sugar levels above 125 mg/dL indicate diabetes.Usually, fasting blood tests are performed first thing in the morning following an overnight fast (meaning eight hours without food). Fasting levels between 100 mg/dL to 125 mg/dL are borderline high and may suggest prediabetes.
Blood sugars rise after a meal. One to two hours after eating, blood sugars should be back down to 180 mg/dL or less. Higher than 180 mg/dL is hyperglycemia.
Another method for tracking high blood sugar is the hemoglobin A1C test. Hemoglobin A1C reflects average blood sugar control over the past three months. Measured in a percentage, an A1C level between 5.7% and 6.4% is a sign of chronic hyperglycemia and may indicate prediabetes. A reading of 6.5% or higher indicates diabetes.
Hypoglycemiais usually diagnosed when blood sugar drops below 70 mg/dL. Not everyone shows symptoms at this level, and some people exhibit symptoms before blood sugars get this low. Serious hypoglycemia causes neurological symptoms, like confusion and lethargy.
Treatment varies for hyperglycemia and hypoglycemia.
Hyperglycemia can be treated immediately with exercise or medication or treated longer-term through dietary changes and losing excess body weight. Iflifestyle changesare unsuccessful, your healthcare provider may suggest starting or adjusting your treatment plan.
If blood sugars are above 240 mg/dL, you may be advised to check for ketones and hold off on working out.
Fast-acting carbohydrates reverse hypoglycemia in a matter of minutes. Sugary foods without fat or protein are quickly converted into sugar, boosting low blood levels. Glucose tablets or gel, fruit juice, regular soft drinks, honey, and sugary candy are a few examples.
Once consumed, blood sugars should be rechecked in 15 minutes and retreated if they have not risen above 70 mg/dL.If blood sugars are moving in the right direction, a more balanced snack or meal can help maintain stable blood sugars.
Working with your healthcare provider will help you avoid sudden spikes and dips in blood sugar that require emergency treatment.
Untreated hyperglycemia can damage the nerves, blood vessels, tissues, and organs. High blood sugars raise heart attack and stroke risk and lead to blindness and kidney disease.
Luckily, regular monitoring with blood sugar and A1C tests makes it possible to adjust yourtreatment planand ward off the negative long-term effects of high blood sugar (while also preventing dangerous lows).
Blood sugar fluctuations can be scary and frustrating. Finding others with similar struggles can make it easier to cope with a diabetes diagnosis. Ask your provider about group education for type 1, type 2, or gestational diabetes to learn more about your condition and get tips from those who get it.
With a little trial and error and your healthcare team’s support, managing blood sugar doesn’t have to feel overwhelming.
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.National Institute of Diabetes and Digestive and Kidney Diseases.What is diabetes?American Diabetes Association.Diabetes & DKA (ketoacidosis).American Diabetes Association.Hyperglycemia (high blood glucose).Ramachandran A.Know the signs and symptoms of diabetes.Indian J Med Res. 2014;140(5):579-581.American Diabetes Association.Low blood glucose (hypoglycemia).Mouri Mi, Badireddy M.Hyperglycemia. In:StatPearls. StatPearls Publishing; 2024.NIH National Institute of Diabetes and Digestive and Kidney Diseases.Low blood glucose.American Diabetes Association Professional Practice Committee.2. Classification and diagnosis of diabetes:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S17-S38. doi:10.2337/dc22-S002Centers for Disease Control and Prevention.Manage blood sugar.American Diabetes Association Professional Practice Committee.6. Glycemic targets:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S83-S96. doi:10.2337/dc22-S006
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.National Institute of Diabetes and Digestive and Kidney Diseases.What is diabetes?American Diabetes Association.Diabetes & DKA (ketoacidosis).American Diabetes Association.Hyperglycemia (high blood glucose).Ramachandran A.Know the signs and symptoms of diabetes.Indian J Med Res. 2014;140(5):579-581.American Diabetes Association.Low blood glucose (hypoglycemia).Mouri Mi, Badireddy M.Hyperglycemia. In:StatPearls. StatPearls Publishing; 2024.NIH National Institute of Diabetes and Digestive and Kidney Diseases.Low blood glucose.American Diabetes Association Professional Practice Committee.2. Classification and diagnosis of diabetes:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S17-S38. doi:10.2337/dc22-S002Centers for Disease Control and Prevention.Manage blood sugar.American Diabetes Association Professional Practice Committee.6. Glycemic targets:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S83-S96. doi:10.2337/dc22-S006
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.National Institute of Diabetes and Digestive and Kidney Diseases.What is diabetes?American Diabetes Association.Diabetes & DKA (ketoacidosis).American Diabetes Association.Hyperglycemia (high blood glucose).Ramachandran A.Know the signs and symptoms of diabetes.Indian J Med Res. 2014;140(5):579-581.American Diabetes Association.Low blood glucose (hypoglycemia).Mouri Mi, Badireddy M.Hyperglycemia. In:StatPearls. StatPearls Publishing; 2024.NIH National Institute of Diabetes and Digestive and Kidney Diseases.Low blood glucose.American Diabetes Association Professional Practice Committee.2. Classification and diagnosis of diabetes:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S17-S38. doi:10.2337/dc22-S002Centers for Disease Control and Prevention.Manage blood sugar.American Diabetes Association Professional Practice Committee.6. Glycemic targets:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S83-S96. doi:10.2337/dc22-S006
Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.
National Institute of Diabetes and Digestive and Kidney Diseases.What is diabetes?
American Diabetes Association.Diabetes & DKA (ketoacidosis).
American Diabetes Association.Hyperglycemia (high blood glucose).
Ramachandran A.Know the signs and symptoms of diabetes.Indian J Med Res. 2014;140(5):579-581.
American Diabetes Association.Low blood glucose (hypoglycemia).
Mouri Mi, Badireddy M.Hyperglycemia. In:StatPearls. StatPearls Publishing; 2024.
NIH National Institute of Diabetes and Digestive and Kidney Diseases.Low blood glucose.
American Diabetes Association Professional Practice Committee.2. Classification and diagnosis of diabetes:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S17-S38. doi:10.2337/dc22-S002
Centers for Disease Control and Prevention.Manage blood sugar.
American Diabetes Association Professional Practice Committee.6. Glycemic targets:Standards of medical care in diabetes—2022.Diabetes Care. 2022;45(Supplement_1):S83-S96. doi:10.2337/dc22-S006
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