Friends, many of us are familiar with Type 1 Diabetes (autoimmune destruction of insulin –producing cells) and Type 2 Diabetes ( insulin resistance with relative insulin deficiency). However, diabetes is not a single disease. There are several other forms caused by genetic defects, hormonal disorders, pancreatic diseases, medication and pregnancy. Understanding these lesser-known types of diabetes is crucial because their treatment, prognosis, and complications may differ significantly from Type 1 or Type 2 diabetes.
Given below are the Other Types of Diabetes
1 Gestational Diabetes Mellitus (GDM)- It is the diabetes diagnosed during pregnancy in women who did not previously have diabetes.
It happens because, when pregnancy hormones (like human placental lactogen) increase, insulin resistance. Some women can not produce enough insulin to compensate.
Risk Factors: Obesity, family history of diabetes, previous large baby (>4kg), PCOs, Age>30, and Indian ethnicity (higher risk).
Why it matters: Can cause large babies, risk of cesarean delivery, low blood sugar in newborn, and increased future risk of Type 2 diabetes in the mother.
Treatment: Diet and exercise, insulin (if needed), and sometimes metformin tablets.
2 Maturity-Onset Diabetes of the Young (MODY)- A genetic form of diabetes caused by a mutation in a single gene affecting insulin production.
Key Features: Diagnosed before age 25, Strong family history (autosomal dominant inheritance), Not obese, and No autoimmune markers.
The two main types in this category are
MODY 2 –mild stable diabetes
MODY 3-progressive and sensitive to sulfonylureas.
Treatment- depends on Type: Some need only diet control, some respond to oral medications. Insulin is rarely required.
3 Latent Autoimmune Diabetes in Adults (LADA)- It is often called Type 1.5 Diabetes. It is autoimmune diabetes like Type 1, but occurs in adults (>30 years), and progresses slowly.
Key Features: Initially misdiagnosed as Type 2, Positive autoimmune antibodies, Gradual insulin requirement over months/years.
Why it matters: Oral diabetes drugs may stop working early. These patients eventually require insulin.
4 Secondary Diabetes (Due to Other Medical Conditions)- Diabetes can develop as a result of other diseases.
A Pancreatic Diabetes (Type 3c Diabetes)- It is caused by damage to the pancreas due to: Chronic pancreatitis, Pancreatic cancer, Pancreatic surgery and Cystic Fibrosis.
Features: Both insulin and digestive enzyme deficiency, Weight loss and Malabsorption.
Treatment: Insulin and Pancreatic enzyme supplements.
B Endocrine Disorders Causing Diabetes– Certain hormonal disorders increase blood sugar: Cushing syndrome (excess cortisol), Acromegaly (excess growth hormone), Hyperthyroidism, and Pheochromocytoma.
Treating the above conditions often improves diabetes.
5 Drug-Induced Diabetes
Some medicines can cause high blood sugar: Steroids (very common cause), Antipsychotics, Some HIV medication, Post-organ transplant drugs, and certain chemotherapy drugs. In most cases, diabetes improves after stopping the drug.
6 Neonatal Diabetes
It is one of the rare diabetes which is diagnosed before 6 months of age.
Types: Transient neonatal diabetes (temporary) and permanent neonatal diabetes.
Cause: Genetic mutations affecting insulin production.
Treatment: Some forms respond better to oral sulfonylureas rather than insulin.
7 Wolfram Syndrome
A rare genetic disorder characterised by: Diabetes mellitus, Diabetic insipidus, Optic nerve damage, and Hearing loss. It usually begins in childhood.
8 Brittle Diabetes
Not a separate type, but refers to: Severe, unstable blood sugar fluctuations, Frequent hospital admission, and is often seen in Type 1 patients.
Causes may include: Psychological stress, eating disorders,& Hormonal issues.
9 Double Diabetes
A person with Type 1 diabetes And Insulin resistance (features of Type 2). This is mostly common in overweight Type 1 patients.
Why Correct Diagnosis Matters: Misclassification can lead to:
- Wrong medications
- Unnecessary Insulin
- Poor sugar control
- Increased complications
For example:
- MODY may respond better to tablets than insulin
- LADA needs earlier insulin therapy.
- Type 3c requires enzyme supplements along with insulin.
When to Suspect a Rare Type of Diabetes?
- Very young diagnosis (<6 months age)
- Strong family history across generations.
- Lean person with diabetes.
- Poor response to standard treatment
- History of pancreatic disease.
- Sudden diabetes after steroid use.
- Diabetes during pregnancy.
In the end, Diabetes is not just Type 1 or Type 2. There are multiple other forms, each with different causes, treatment approaches, and long-term risks. Proper diagnosis using blood tests, genetic testing, antibody tests, and clinical history is essential for effective management. If blood sugar behaves unusually or does not respond to standard treatment, then it is time the disease should be evaluated for a less common type of diabetes.
Anil Malik
Mumbai, India
25th February 2026