Diabetes mellitus is a group of metabolic conditions whose common feature is chronically elevated blood glucose (hyperglycemia). Insulin — a hormone of the pancreas — normally moves glucose from the blood into the body's cells, where it is used as energy. In diabetes, this mechanism doesn't work properly: either very little or no insulin is produced (Type 1), or the cells no longer respond to it well enough (Type 2).
The result: glucose builds up in the blood while the cells "starve." Persistently elevated blood glucose can gradually damage blood vessels, nerves and organs — often over years, before noticeable symptoms appear.
In Germany, the prevalence of diagnosed diabetes was around 10.3% of adults according to the Robert Koch Institute (2024 analysis). Prevalence has risen substantially over recent decades.¹˒²
2. Type 1 vs. Type 2 — the differences at a glance
Type 1Autoimmune disease
Immune system destroys the beta cells of the pancreas
Absolute insulin deficiency — generally little or no insulin of one's own
Usually begins in childhood/adolescence; possible at any age in principle
NOT caused by lifestyle
Lifelong insulin therapy is generally required
Modern therapy: CGM and AID systems (hybrid closed loop)
The core difference
In Type 1, insulin is generally completely absent (autoimmune). In Type 2, enough insulin is usually still present, but the cells no longer respond to it well enough. Type 1 is NOT caused by lifestyle and cannot be treated by lifestyle change alone — insulin therapy is generally essential.
3. Other forms of diabetes
Gestational diabetes: First detected during pregnancy — generally resolves after birth. Care should always be closely overseen by your treating doctors.
LADA (Latent Autoimmune Diabetes in Adults): An autoimmune form starting in adulthood, often initially mistaken for Type 2. Typically: lean patients without marked insulin resistance and with detectable autoantibodies. Insulin therapy is generally needed over time.
MODY (Maturity Onset Diabetes of the Young): A genetically caused form, usually with onset before age 25. Several subtypes with different treatments.
Secondary diabetes: Triggered by other conditions (e.g. pancreatitis, Cushing's syndrome, cystic fibrosis) or certain medications (e.g. cortisone, some antipsychotics).
Many people with Type 2 have no clear symptoms for a long time
The diabetes is often only detected at routine check-ups — or once complications have already developed. So: from around your mid-30s onwards, have your blood glucose checked at your health check-up.
5. Diagnosis: which values matter?
The diagnosis is generally made using defined lab values. For a reliable diagnosis, the current NVL usually requires two pathological lab values.³
Fasting blood glucose ≥ 126 mg/dL (7.0 mmol/L) — generally confirmed on two different days
HbA1c ≥ 6.5% (48 mmol/mol) — the "long-term blood glucose" of the past 2–3 months
2-hour OGTT value ≥ 200 mg/dL (11.1 mmol/L)
Random blood glucose ≥ 200 mg/dL with typical symptoms at the same time
Type 1 or Type 2? Differentiation
Autoantibodies (e.g. GAD antibodies, IA-2 antibodies, ZnT8 antibodies) — usually positive in Type 1, negative in Type 2
C-peptide — low in Type 1 (little endogenous insulin), normal/elevated in Type 2
Clinical picture: Age, BMI, family history and course (acute vs. gradual)
Don't miss LADA
In adults, LADA (autoimmune diabetes in adulthood) is often initially misclassified as Type 2. An autoantibody test can be useful in lean patients without a family history.
A combination of a long-acting basal insulin (e.g. insulin glargine or degludec) and a short-acting bolus insulin with meals (e.g. insulin lispro or aspart). Requires regular blood glucose measurements, carbohydrate estimation and individually adjusted dose calculation — together with your diabetes team.
Option 2Insulin pump + CGM + AID system (hybrid closed loop)
An insulin pump delivers insulin continuously, while a CGM sensor measures glucose at short intervals. AID systems partly adjust insulin delivery automatically based on the current glucose value. Studies often show better metabolic control and fewer severe hypoglycemic episodes compared with purely manual therapy.⁴
Type 2 diabetes is generally treated in steps — first with lifestyle adjustments, then with medications if needed. Which medications are appropriate in the individual case is always decided by your treating doctor on the basis of the current NVL (National Disease Management Guideline).³
Step 0Lifestyle — the first step
Dietary change (e.g. Mediterranean, high in fiber), regular exercise and moderate weight loss. In the first years of the condition, remission is even possible in individual cases. Lifestyle intervention in prediabetes can significantly reduce the risk of developing Type 2 diabetes.
Step 1Metformin — first-line standard therapy
Has been the standard therapy for decades. Among other effects, it suppresses glucose production in the liver and improves insulin sensitivity. Generally does not cause hypoglycemia. Gradual dose escalation and taking it with food are commonly recommended to reduce gastrointestinal complaints.
SGLT2 inhibitors (e.g. empagliflozin, dapagliflozin) have shown additional benefits for the heart and kidneys in studies. GLP-1 receptor agonists (e.g. semaglutide/Ozempic, tirzepatide/Mounjaro) significantly lower blood glucose and can at the same time contribute to weight loss and a cardiovascular benefit in certain patient groups. In people with relevant heart or kidney conditions, the guideline says their use can also be considered early.³
Step 3Insulin — when other options are not enough
When oral medications and GLP-1 receptor agonists are not sufficient, a basal insulin is often added. The transition to insulin is usually not a "failure" of therapy but reflects the natural course of the disease.
DMP Diabetes (German Disease Management Program) — structured education and regular check-ups; enrollment via your statutory health insurance
9. Living with diabetes
Nutrition: A special "diabetic diet" is generally not necessary. A balanced, high-fiber diet with little sugar and few sugary drinks is usually recommended. Estimating carbohydrates is generally required in Type 1 and often helpful in Type 2.
Sport: Regular exercise is generally recommended for both forms of diabetes. It usually improves insulin sensitivity (important in Type 2) and can help keep blood glucose more stable.
Alcohol: Alcohol can increase the risk of hypoglycemia when taken with insulin or sulfonylureas. Learn more: Medication and alcohol.
Travel: Insulin generally needs to be transported cool; an adequate reserve and a doctor's certificate for syringes, pump or CGM in your hand luggage are advisable. Learn more: Medication when traveling.
Emergency: hypoglycemia
Typical warning signs: trembling, sweating, palpitations, ravenous hunger, irritability. Immediate measure: take fast-acting carbohydrates (e.g. glucose tablets), then re-measure. In severe cases with loss of consciousness: call 112 — and if trained, administer a glucagon rescue medication.
How brite helps you with diabetes
brite brings structure to your diabetes therapy — whether Type 1, Type 2 or another form of diabetes.
Medication reminders — metformin, insulin, weekly GLP-1 injection or sensor change: brite reliably reminds you. Set up a reminder
Interaction check — check diabetes medications in combination with blood pressure drugs, statins or painkillers. Check now
Health tracking — document blood glucose, HbA1c, weight and blood pressure over time. Track your history
Digital medication plan — all medications clearly laid out for your diabetes specialist, GP and pharmacy. Go to medication plan
Type 1 is an autoimmune disease — the body generally no longer produces its own insulin, and lifelong insulin therapy is required. Type 2 is mostly characterized by insulin resistance, often combined with overweight. Here treatment starts with lifestyle, then medications like metformin, SGLT2 inhibitors or GLP-1 receptor agonists are added; insulin often only becomes necessary in later stages.
Type 1 is not curable according to current knowledge — insulin therapy is generally required for life. In Type 2, remission may be possible, particularly through weight loss and lifestyle change in the first years of the condition. Remissions have also been described after bariatric surgery. There is, however, a risk of relapse.³
Fasting blood glucose normally below 100 mg/dL (5.6 mmol/L); HbA1c below 5.7%. Prediabetes is generally defined as a fasting glucose of 100 to 125 mg/dL or HbA1c 5.7–6.4%. A diabetes diagnosis is generally made from a fasting glucose ≥ 126 mg/dL or HbA1c ≥ 6.5%.³
It's generally not that simple. Type 1 has nothing to do with diet — it is an autoimmune disease. In Type 2, overweight plays a major role — and sugar can contribute to that. But genetics, lack of exercise, ultra-processed foods and social factors also matter.
HbA1c reflects the average blood glucose of the past two to three months. A value below 5.7% is generally considered normal. From around 6.5%, it counts as a diabetes criterion. An advantage: the test does not require fasting.³
Both are GLP-1 receptor agonists used in Type 2 diabetes. They can significantly lower blood glucose, affect appetite and lead to weight loss in some patients. Ozempic contains semaglutide, Mounjaro contains tirzepatide. For Type 2 diabetes, they are generally covered by statutory health insurance in Germany.
CGM stands for Continuous Glucose Monitoring. A small sensor under the skin measures glucose at short intervals and generally transmits it to a smartphone or receiver. CGMs are now standard in Type 1 diabetes and are increasingly used in Type 2 on insulin therapy as well.
With warning signs, take fast-acting carbohydrates immediately (e.g. glucose tablets or a sugary drink) and re-measure after a few minutes. In severe cases with reduced consciousness or unconsciousness: call 112 — and if trained, administer a glucagon rescue medication. Never put anything in the mouth of an unconscious person.
Type 1 diabetes cannot currently be reliably prevented. With Type 2 diabetes, the risk is in many cases influenceable: maintaining a healthy weight, regular exercise, a balanced diet and not smoking are considered key building blocks. Studies of lifestyle intervention in prediabetes have shown that the risk of developing Type 2 diabetes can be significantly reduced.
Medical disclaimer: This article is for general information only and is not a substitute for medical advice, diagnosis or treatment. Dosages, choice of medication and treatment goals are always determined individually by your treating doctor. If diabetic ketoacidosis is suspected (e.g. fruity-sweet breath odor, vomiting, impaired consciousness) or in a severe hypoglycemic episode, call 112 immediately. Diabetes medications should not be stopped on your own. Last updated: April 2026.
