Diabetes mellitus is a metabolic disorder resulting in hyperglycemia and disturbances of carbohydrate, fat, and protein metabolism. It is caused by a relative or complete lack of insulin or a defect in the normal action of insulin. It is one of the most common chronic diseases, with increasing incidence worldwide.
Some patients present with acute symptoms. Others remain undiagnosed owing to the subclinical phase of the disease, particularly in type 2 diabetes.
People with diabetes are at increased risk of cardiovascular disease, peripheral vascular disease, and stroke as well as specific complications including retinopathy, nephropathy, and diabetic neuropathy.
Treatment of patients with type 1 diabetes requires insulin replacement.
Type 2 diabetes may be controlled by dietary and lifestyle adaptations, a variety of possible types of oral hypoglycemics, or injectable therapy, e.g. with insulin.
The distinction between diabetes types 1 and 2 is not always apparent and there may be some overlap.
Type 1 diabetes has the following features:
- Classically a disease of the young, but can have its onset at any age
- Usually rapid onset
- Typically presents with sudden loss of weight, polyuria, thirst, and elevated blood glucose
- May present acutely with symptoms of diabetic ketoacidosis
Type 2 diabetes has the following features:
- Represents 90% of all patients with diabetes of any type
- Classically a disease of the middle-aged and elderly, although cases are increasing in early adulthood and childhood
- Usually insidious onset
- A family history of diabetes is not unusual
- May be preceded by a period of impaired glucose tolerance, which is often asymptomatic
Long-term monitoring and diabetes care is improved when a well-organized healthcare team works in partnership with the patient and caregiver.
