This page compiles our content related to diabetes. For further information on diagnosis and treatment, follow the links below to our full BMJ Best Practice topics on the relevant conditions and symptoms.
Diabetes is a general term for disorders characterized by polyuria. It usually refers to diabetes mellitus, a common chronic syndrome of impaired carbohydrate, protein, and fat metabolism, owing to insufficient secretion of insulin and/or target-tissue insulin resistance. Complications of diabetes mellitus include both macrovascular (cardiovascular) and microvascular (retinopathy, nephropathy, or neuropathy) sequelae.
Diabetes insipidus (DI) is much less common and refers to disorders of vasopressin secretion (central DI) or action (nephrogenic DI), resulting in urinary concentrating abnormality.
Common disorder characterized by insulin resistance and relative insulin deficiency. Most patients are asymptomatic and are diagnosed through screening (abnormal fasting plasma glucose, hemoglobin A1c, and/or oral glucose tolerance test). Strong risk factors include older age, overweight/obesity, physical inactivity, prior gestational diabetes, prediabetes, nonwhite ancestry, family history of diabetes, or polycystic ovary syndrome.
Obesity, leading to insulin resistance, is the primary cause of type 2 diabetes in children. The incidence of type 2 diabetes in youths (age 10 to 19 years) is increasing. Commonly accompanied by acanthosis nigricans (90% to 95% of patients).
GDM is diagnosed in the second or third trimester of pregnancy (usually between 24 to 28 weeks of gestation) on the basis of abnormal glucose tolerance testing. Women at high risk of type 2 diabetes are tested at their first prenatal visit to detect preexisting (overt) diabetes. Risk factors for GDM include advanced maternal age (>40 years), obesity, personal history of gestational diabetes or macrosomia of previous child, polycystic ovary syndrome, nonwhite ancestry, and family history of diabetes mellitus.
DKA and hyperosmolar hyperglycemic states are acute metabolic emergencies. DKA is characterised by absolute insulin deficiency and is the most common acute hyperglyaemic complication of type 1 diabetes. Successful treatment includes correction of volume depletion, hyperglycemia and ketosis/acidosis, electrolyte imbalances, and comorbid precipitating events (e.g., infection), along with frequent monitoring.
Severe hyperglycemia, hyperosmolality, and volume depletion, in the absence of severe ketoacidosis. Occurs most commonly in older patients with type 2 diabetes, with high mortality. Treatment includes correction of fluid deficit and electrolyte abnormalities, and intravenous insulin.
Coronary artery disease and stroke are the most common manifestations, and account for most deaths in people with diabetes. Modification of cardiovascular risk factors (e.g., hypertension, dyslipidemia) are important long-term treatment issues. 
Defined by albuminuria (increased urinary albumin excretion is defined as 30 mg/g) and progressive reduction in estimated glomerular filtration rate (eGFR) in the setting of a long duration of diabetes (>10 years' duration of type 1 diabetes; may be present at diagnosis in type 2 diabetes), and is typically associated with retinopathy. Symptoms may be absent until the disease is advanced.
The most common chronic complication in diabetes affecting different parts of the nervous system and presenting with diverse clinical manifestations. Peripheral neuropathy may present as loss of sensation, painless ulcers on pressure points, or pain, although many patients are asymptomatic.
Encompasses the conditions of diabetic foot ulcer (i.e., a full-thickness epithelial defect below/distal to the ankle) and diabetic foot infections (i.e., any soft-tissue or bone infection occurring in the diabetic foot). Prevention and/or healing of diabetic foot ulcers helps to prevent infections and minimizes the risk of limb loss.
Refers to identification and treatment of hyperglycemia in the hospital, in patients with either preexisting diabetes or new-onset hyperglycemia. The development of hyperglycemia during acute medical or surgical illness may not be a physiologic or benign condition but rather a marker of poor clinical outcomes and increased mortality.
Cluster of common abnormalities, including insulin resistance, impaired glucose tolerance, abdominal obesity, reduced high-density lipoprotein-cholesterol levels, elevated triglycerides, and hypertension. However, this syndrome is not universally accepted as more clinically useful than assessment of individual cardiovascular risk factors.
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This overview has been compiled using the information in existing sub-topics.
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