Nelson’s Medical • Endocrine & Metabolic Health
Diabetes: Types, Symptoms, Diagnosis, Treatment, and Living Well
Diabetes is common, manageable, and—when ignored—capable of causing serious harm. This guide explains what diabetes is, how it’s diagnosed, how treatment works, and how to reduce short-term emergencies and long-term complications.
At a glance
- Diabetes = high blood sugar over time.
- Caused by insulin deficiency, insulin resistance, or both.
- Management reduces emergency risk now and complications later.
Most common types
- Type 1: little/no insulin (autoimmune).
- Type 2: insulin resistance + reduced insulin over time.
- Gestational: pregnancy-related insulin resistance.
Urgent warning signs
Seek urgent help for persistent vomiting, severe abdominal pain, trouble breathing, confusion, or extreme drowsiness.
What diabetes is (and what it isn’t)
Diabetes mellitus is a condition where blood glucose (blood sugar) stays higher than normal. Glucose is a key fuel for the body. The pancreas makes insulin, a hormone that helps move glucose from the bloodstream into cells.
Diabetes happens when the body doesn’t make enough insulin, can’t use insulin effectively (called insulin resistance), or both. Over time, high blood sugar can damage blood vessels and nerves, raising the risk of heart disease, stroke, kidney disease, vision problems, and nerve damage—especially in the feet.
Plain-language core
Diabetes is a long-term blood sugar regulation problem. Treatment is about safer ranges and fewer dangerous swings—not perfection.
Diabetes is not a moral failure and it isn’t simply caused by eating sugar. Food patterns matter, but genetics, hormones, pregnancy, medications, sleep, stress, and other health factors also shape risk and control.
Types of diabetes
Type 1 diabetes
Usually autoimmune damage to insulin-producing cells → little or no insulin. Type 1 can begin in childhood or adulthood. Insulin therapy is required.
Type 2 diabetes
Insulin resistance plus reduced insulin production over time. Often gradual onset, and symptoms may be mild or absent early. Treatment includes lifestyle changes, medications, and sometimes insulin.
Gestational diabetes
Develops during pregnancy due to increased insulin resistance. Usually improves after delivery but increases future type 2 risk.
Prediabetes
Blood sugar higher than normal but below diabetes range. It’s a warning sign—many people reduce progression risk with targeted changes.
Symptoms and warning signs
Some people—especially with early type 2—may have few or no symptoms. Common signs include:
Common symptoms
- Increased thirst
- Frequent urination
- Fatigue
- Blurred vision
- Increased hunger
- Slow healing cuts or frequent infections
- Unexplained weight loss (more common in type 1)
Danger signs (seek urgent care)
- Persistent vomiting
- Severe abdominal pain
- Rapid or deep breathing
- Fruity-smelling breath
- Severe weakness or dehydration
- Confusion or extreme drowsiness
These may indicate emergencies like DKA or HHS.
Diagnosis: A1C and glucose tests
Diabetes is diagnosed with blood tests. Common tests include:
A1C
Estimates average blood sugar over ~2–3 months. Useful for long-term patterns.
Fasting plasma glucose
Measures blood sugar after at least 8 hours without eating.
OGTT
Measures blood sugar response after a glucose drink. Often used in pregnancy.
Random plasma glucose
Sometimes used when symptoms are present and glucose is clearly elevated.
Treatment: lifestyle, medications, insulin
Lifestyle foundations
- Nutrition: minimally processed foods, adequate protein/fiber, consistent carbohydrate patterns.
- Activity: aerobic + resistance training improves insulin sensitivity; post-meal walks can help reduce spikes.
- Sleep: poor sleep can increase insulin resistance.
- Stress: stress hormones can raise glucose; coping strategies matter.
- Weight management (when appropriate): modest loss can improve insulin sensitivity for many with type 2.
Medications
Medications are chosen based on diabetes type, glucose patterns, kidney and heart health, risk of low blood sugar, side effects, cost, and personal preferences. Different classes work in different ways.
Insulin therapy
Insulin is required for type 1 diabetes and may be needed for type 2 in certain situations (illness, pregnancy, surgery, or later stages). Needing insulin is not a failure—it can be the safest tool to protect the body.
Monitoring and daily patterns
Monitoring helps you connect cause-and-effect: meals, activity, stress, sleep, and medication timing. The goal is learning patterns and reducing dangerous swings.
Fingerstick meter
Targeted checks: fasting, before/after meals, bedtime, symptoms.
CGM
Trends all day/night + alerts for highs and lows.
A1C
Long-term average marker; helps estimate overall control.
Low blood sugar (hypoglycemia)
Hypoglycemia is more likely in people who use insulin or certain medications. Symptoms can include shakiness, sweating, fast heartbeat, hunger, irritability, headache, dizziness, or confusion.
High blood sugar (hyperglycemia)
Hyperglycemia can cause thirst, frequent urination, fatigue, and blurred vision. It may worsen during illness, stress, missed medications, or changes in eating/activity.
Seek urgent evaluation if high blood sugar is paired with persistent vomiting, dehydration, trouble breathing, confusion, or severe weakness.
Complications and prevention
Over time, uncontrolled diabetes can injure both large and small blood vessels and nerves. Preventive care and steady control reduce risk.
Common complications
- Heart disease and stroke
- Kidney disease
- Eye disease (retinopathy)
- Nerve damage (neuropathy)
- Foot ulcers and slow wound healing
High-impact prevention
- Safer glucose ranges with a sustainable plan
- Blood pressure and cholesterol management as recommended
- Avoid smoking/vaping
- Routine eye, kidney, and foot screening
- Stay current on vaccinations
Daily life: food, activity, sleep, and stress
Food without the chaos
There is no single “perfect diabetes diet.” Sustainable patterns beat extreme rules. Many people do well with balanced meals, consistent carbohydrates, more fiber, and fewer ultra-processed foods. Monitoring can help identify personal triggers and patterns.
Movement as glucose medicine
Muscles use glucose efficiently, especially during and after activity. Regular movement improves insulin sensitivity. If you use insulin or medications that can cause lows, ask your clinician about safe exercise planning.
Sleep and stress
Poor sleep and chronic stress can raise blood sugar via hormones. Improving sleep consistency and adding stress tools (breathing, counseling, journaling, social support) can improve control over time.
Special situations
Pregnancy (gestational diabetes)
Management focuses on safer glucose ranges for pregnancy, often with a nutrition plan and monitoring. Some people need medication or insulin. After delivery, follow-up screening is important because long-term diabetes risk is higher.
Illness (“sick days”)
Illness can raise blood sugar even when eating less. Many people benefit from a sick-day plan: hydration, more frequent checks, and medication guidance. Some may be advised to check ketones during illness or persistent highs.
When to seek urgent care
Call your clinician (same day/next day)
- Repeated high readings despite your plan
- Frequent low blood sugar episodes
- New numbness, foot sores, or vision changes
- Medication side effects or trouble affording meds
- Pregnancy or major life changes requiring plan updates
Seek urgent/emergency care now
- Severe confusion, fainting, seizure, or inability to stay awake
- Inability to safely swallow (possible severe low)
- Persistent vomiting, severe abdominal pain, rapid/deep breathing, fruity breath
- Suspected DKA/HHS, severe dehydration, trouble breathing
- Chest pain or stroke symptoms
Common myths
“If I need insulin, I failed.”
Insulin is a tool. Diabetes can progress. Using insulin can protect organs and reduce risk.
“Only sugar causes diabetes.”
Risk is shaped by genetics, hormones, medications, sleep, stress, and lifestyle patterns.
“I’ll feel it if my sugar is high.”
Many people don’t. Monitoring and lab tests catch problems early.
“Carbs are evil forever.”
Carb awareness matters, but sustainable patterns beat extreme restrictions.
Quick FAQ
Can type 2 diabetes be prevented?
Many people reduce risk through healthier eating patterns, regular activity, weight management, and adequate sleep. Prediabetes is a key opportunity for prevention.
Can diabetes be cured?
Diabetes is usually not “cured,” but it can be well controlled. Some people with type 2 diabetes achieve remission with major lifestyle changes and/or bariatric surgery, but ongoing monitoring remains important.
What should I track day to day?
Many people track glucose readings or CGM trends, medication timing, meals, activity, and sleep. The goal is learning patterns and preventing dangerous swings.