8 Types of Diabetes (Including Causes, Symptoms & Treatment)

Types of diabetes include type 1, type 2, and gestational diabetes mellitus, which can be caused by impaired insulin production or insulin resistance. 

Other types of diabetes include diabetes insipidus, latent autoimmune diabetes in adults (LADA), and maturity-onset diabetes of the young (MODY), which has characteristics of both type 1 and type 2 diabetes.

The type of diabetes is diagnosed by an endocrinologist or primary care provider who can prescribe the most adequate treatment depending on the condition. This may include diet changes, exercise, or the use of oral diabetes medications or insulin.

Main types

The principal types of diabetes are: 

1. Type 1 diabetes

Type 1 diabetes is a less common type of diabetes in which the pancreas produces little or no insulin, resulting in very high levels of glucose in the blood.

This type of diabetes is an autoimmune disease in which the immune system attacks and destroys beta cells in the pancreas, mistaking them for intruder cells.

Type 1 diabetes generally emerges in childhood or adolescence, presenting with symptoms like increased urination, excessive hunger and thirst, or unexplained weight loss. 

Treatment for type 1 diabetes involves daily injections with different types of insulin or use of an insulin pump to reduce blood sugar levels in the body.

2. Type 2 diabetes

Type 2 diabetes is the most common type of diabetes and is characterized by insulin resistance (the inability of the body to use the insulin it has), impaired insulin production, or both. 

Type 2 diabetes is more common in people over 40 and is typically related to genetics or other factors like a sedentary lifestyle. It does not usually cause symptoms at first.

High blood glucose levels can, however, lead to symptoms like dry mouth, constant thirst, poor wound healing, or blurry vision.

Treatment of type 2 diabetes typically involves lifestyle changes, exercise, and/or the use of medications like metformin, gliclazide, semaglutide, and dapagliflozin, and, in some cases, insulin.

3. Type 3 diabetes

Type 3 diabetes is a type of diabetes that is believed to be related to the inability of the brain to respond to insulin. 

This type of diabetes is not officially recognized by the medical community, and occurs primarily in people with Alzheimer's disease.

4. Gestational diabetes

Gestational diabetes is a type of diabetes that is diagnosed for the first time during pregnancy.

This type of diabetes can appear after week 24 of pregnancy and is caused by a dysfunction in insulin production and function in the body.

Gestational diabetes is more common in people who have a strong family history of diabetes or unhealthy lifestyle habits, such as eating a diet high in fat and sugar.

Symptoms of gestational diabetes are similar to those of type 2 diabetes and treatment involves dietary changes and exercise. Medications like insulin may be necessary if lifestyle changes are not enough to manage the condition. This type of diabetes tends to go away after the baby is born.

Read about signs of gestational diabetes.

5. Maturity-onset diabetes of the young

Maturity-onset diabetes of the young (MODY) is a rare type of diabetes that occurs in young people. It is a milder form than type 1 diabetes and is more similar to type 2 diabetes. 

This type of diabetes is caused by a single gene mutation inherited from one of the parents.

The onset of MODY typically occurs before the age of 25, causing symptoms like increased urination, thirst, or frequent infections. 

MODY can be treated with medications like glibenclamide or metformin, for example, or insulin injections.

6. Latent autoimmune diabetes in adults

Latent autoimmune diabetes in adults (LADA) is a type of autoimmune diabetes that occurs in adults.

This type of diabetes is typically suspected in adults with type 2 diabetes who present with very rapid onset of pancreatic dysfunction that requires use of insulin early on. 

7. Diabetes insipidus

Diabetes insipidus is a rare condition caused by decreased production of antidiuretic hormone (ADH) that regulates urine production, or kidney issues that make them stop responding to this hormone.

This condition causes a person to urinate more and results in an excessive loss of water in the body, leading to dehydration and increased thirst.  

The treatment of diabetes insipidus varies based on the cause and may involve the use of hormones, diuretics, or anti-inflammatories. 

8. Secondary diabetes

Secondary diabetes is a type of diabetes caused by other health problems, and can lead to the development of type 1 or type 2 diabetes.

The main causes of secondary diabetes include:

• Diseases of the pancreas, such as a tumor, infection, or fibrosis;
• Endocrine disorders, such as Cushing's disease, pheochromocytoma, and acromegaly, for example;
• Diabetes triggered by the use of medications, such as corticosteroids.

This type of diabetes is typically managed by treating the underlying health condition that is causing it, however the use of oral diabetes medications or insulin may also be indicated. 

Confirming a diagnosis

An endocrinologist or primary care provider can diagnosis different types of diabetes based on an evaluation of symptoms and symptom onset, lab test results, and family history of diabetes. 

Your doctor or healthcare provider may order tests like a fasting blood glucose, hemoglobin A1c, or glucose tolerance test to help confirm or rule out a diagnosis.

The workup for diabetes insipidus may also involve a 24 hour urine collection or water deprivation test.