Diabetes: Symptoms, Types, Causes & Treatment
Learn how diabetes affects blood sugar and insulin, understand the different types, recognize common symptoms, explore testing and treatment, and learn how diabetes can be managed over time.
What is diabetes?
Diabetes affects how your body manages glucose.
Diabetes is a condition involving problems with the way the body makes or uses insulin. Insulin helps glucose move from the bloodstream into cells where it can be used for energy. When insulin is absent, insufficient or does not work properly, blood glucose can rise.
How insulin helps your body use glucose
Glucose from food enters the bloodstream. Insulin helps your body's cells take up glucose and use it for energy.
Food
Carbohydrates are broken down into glucose.
Bloodstream
Glucose enters the blood after digestion.
Insulin
Insulin helps glucose enter cells.
Energy
Cells use glucose to support everyday activities.
Diabetes can take different forms
The type of diabetes affects how it develops, how it is treated and how it is managed.
Type 1 Diabetes
The immune system attacks insulin-producing cells in the pancreas, resulting in little or no insulin production.
Insulin requiredType 2 Diabetes
The body does not use insulin effectively and may also gradually produce less insulin.
Most common typeGestational Diabetes
Diabetes that develops during pregnancy and can affect blood glucose management during that period.
Pregnancy-relatedCommon symptoms of diabetes
Some people have mild or no noticeable symptoms, particularly in the early stages. Symptoms can vary by person and type.
Increased Thirst
Feeling unusually thirsty.
Frequent Urination
Needing to urinate more often.
Increased Hunger
Feeling hungry more frequently.
Fatigue
Feeling unusually tired or weak.
Blurred Vision
Changes in vision can occur.
Unexplained Weight Loss
Weight loss without intentionally trying.
Slow-Healing Wounds
Cuts or wounds may take longer to heal.
Tingling or Numbness
Especially in the hands or feet.
Important: These symptoms can have many possible causes. Symptoms alone cannot confirm diabetes. Appropriate blood-glucose testing is needed for diagnosis.
What can contribute to diabetes?
Diabetes has different causes depending on the type. Type 2 diabetes can involve insulin resistance, genetics and several health and lifestyle factors.
Factors linked with Type 2 diabetes
- Family history of diabetes
- Insulin resistance or prediabetes
- Being overweight or having obesity
- Low levels of physical activity
- High blood pressure
- Abnormal cholesterol or triglyceride levels
- Polycystic ovary syndrome (PCOS)
- Smoking and some lifestyle factors
Why Type 1 is different
- Type 1 diabetes involves an immune-system attack on insulin-producing pancreatic cells.
- It is not caused simply by being overweight or inactive.
- The body produces little or no insulin.
- People with type 1 diabetes need insulin treatment.
How is diabetes diagnosed?
Healthcare professionals use blood-glucose tests and other information to determine whether diabetes or prediabetes is present.
Medical History
Your symptoms, health history and risk factors are reviewed.
Blood Glucose
Blood tests can measure glucose levels at specific times.
A1C Testing
An A1C test provides information about average blood glucose over the preceding months.
Clinical Assessment
Your healthcare professional interprets test results and determines the next steps.
Diabetes monitoring
Ongoing monitoring can help healthcare professionals understand how well diabetes is being managed and whether treatment needs adjustment.
How is diabetes treated?
Treatment depends on the type of diabetes, blood-glucose levels, overall health and individual needs.
Healthy Eating
Nutrition planning can support blood-glucose management.
Physical Activity
Regular activity can help the body use glucose and insulin.
Medicines
Some people need medicines to help manage blood glucose.
Insulin
Insulin is essential for type 1 diabetes and may also be used in some people with type 2.
Monitoring
Regular monitoring helps guide diabetes management.
Diabetes treatment is individualized. Do not start, stop or change diabetes medication or insulin without discussing it with your healthcare professional.
Why diabetes management matters
Persistently high blood glucose can contribute to damage affecting several parts of the body over time.
Heart & Blood Vessels
Diabetes can increase the risk of cardiovascular problems.
Kidneys
Diabetes can affect kidney function over time.
Eyes
Diabetes-related eye problems can affect vision.
Nerves
Nerve damage may cause numbness, tingling or pain.
Feet & Skin
Nerve and circulation problems can contribute to foot complications and slower wound healing.
Oral Health
Diabetes can also be associated with certain oral health problems.
Supporting healthy blood-glucose levels
Lifestyle changes can play an important role in reducing the risk of type 2 diabetes and supporting diabetes management.
Balanced Eating
Build eating habits that support overall health and blood glucose management.
Stay Active
Regular physical activity can help your body use glucose more effectively.
Healthy Weight
For people with overweight or obesity, appropriate weight management can reduce type 2 diabetes risk.
Don't Smoke
Avoiding tobacco supports cardiovascular and overall health.
What are you experiencing?
Select a symptom to learn what it can be associated with. This tool is educational and cannot diagnose diabetes.
Choose a symptom
Select one option below.
Select a symptom to learn more.
When should you talk to a doctor?
New or persistent symptoms, abnormal glucose readings or concerns about diabetes should be discussed with a healthcare professional.
Consider medical evaluation if:
- You're experiencing persistent diabetes-like symptoms.
- Blood glucose readings are repeatedly outside your target range.
- You have risk factors for type 2 diabetes.
- You have been told you have prediabetes.
- You have symptoms that are new or unexplained.
- You need help managing an existing diabetes diagnosis.
Seek urgent medical care if:
- You have severe weakness or significant confusion.
- You lose consciousness.
- You have severe difficulty breathing.
- You have repeated vomiting with severe illness.
- You have symptoms suggesting a serious blood-glucose emergency.
Frequently Asked Questions
Diabetes is a condition in which the body has problems making insulin, using insulin effectively or both, leading to elevated blood glucose.
The main types include type 1 diabetes, type 2 diabetes and gestational diabetes. Prediabetes is a state of elevated blood glucose that does not meet the diagnostic range for diabetes.
Symptoms can include increased thirst, frequent urination, increased hunger, fatigue, blurred vision, unexplained weight loss and tingling or numbness. Some people may have few or no noticeable symptoms.
Diabetes is diagnosed using appropriate blood-glucose tests, which may include fasting glucose, A1C or other glucose testing depending on the situation.
Some risk factors cannot be changed, but healthy eating, regular physical activity, appropriate weight management and avoiding tobacco can help reduce the risk of type 2 diabetes.
Diabetes is generally considered a lifelong condition, although some people with type 2 diabetes can achieve remission. Treatment and management depend on the type of diabetes and individual circumstances.
People with type 1 diabetes need insulin. Some people with type 2 diabetes may also need insulin depending on their blood-glucose control and treatment needs.
Monitoring helps you and your healthcare team understand how well blood glucose is being managed and whether treatment or lifestyle strategies need adjustment.
Medical & Editorial Information
Have Questions About Diabetes?
Understanding your symptoms, blood glucose results and treatment options can help you have a more informed conversation with your healthcare professional.
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