Hyperglycemia may be caused by: diabetes, various (non-diabetic) endocrine disorders (insulin resistance and thyroid, adrenal, pancreatic, and pituitary disorders), sepsis and certain infections, intracranial diseases (e.g. encephalitis, brain tumors (especially if near the pituitary gland), brain haemorrhages, and meningitis) (frequently overlooked), convulsions, end-stage terminal disease, prolonged/major surgeries, excessive eating, severe stress, and physical trauma. Endocrine Chronic, persistent hyperglycaemia is most often a result of diabetes. Several hormones act to increase blood glucose levels and may thus cause hyperglycaemia when present in excess, including: cortisol, catecholamines, growth hormone, glucagon, and thyroid hormones. Hyperglycaemia may thus be seen in: Cushing's syndrome, pheochromocytoma, acromegaly, hyperglucagonemia, and hyperthyroidism. Diabetes mellitus Chronic hyperglycemia that persists even in fasting states is most commonly caused by diabetes mellitus. In fact, chronic hyperglycemia is the defining characteristic of the disease. Intermittent hyperglycemia may be present in prediabetic states. Acute episodes of hyperglycemia without an obvious cause may indicate developing diabetes or a predisposition to the disorder. In diabetes mellitus, hyperglycemia is usually caused by low insulin levels (diabetes mellitus type 1) and/or by resistance to insulin at the cellular level (diabetes mellitus type 2), depending on the type and state of the disease. Low insulin levels and/or insulin resistance prevent the body from converting glucose into glycogen (a starch-like source of energy stored mostly in the liver), which in turn makes it difficult or impossible to remove excess glucose from the blood. With normal glucose levels, the total amount of glucose in the blood at any given moment is only enough to provide energy to the body for 20–30 minutes, and so glucose levels must be precisely maintained by the body's internal control mechanisms. When the mechanisms fail in a way that allows glucose to rise to abnormal levels, hyperglycemia is the result.<unk>  may be the first symptom of immune-mediated diabetes, particularly in children and adolescents. Also, patients with immune-mediated diabetes, can change from modest fasting hyperglycemia to severe hyperglycemia and even<unk>  as a result of stress or an infection. Insulin resistance Obesity has been contributing to increased insulin resistance due to the population's daily caloric intake rising. Insulin resistance increases hyperglycemia because the body becomes over saturated by glucose. Insulin resistance desensitizes insulin receptors, preventing insulin from lowering blood sugar levels. The leading cause of hyperglycemia in type 2 diabetes is the failure of insulin to suppress glucose production by glycolysis and gluconeogenesis due to insulin resistance. Insulin normally inhibits glycogenolysis, but fails to do so in a condition of insulin resistance, resulting in increased glucose production. In the liver, FOXO6 normally promotes gluconeogenesis in the fasted state, but insulin blocks Fox06 upon feeding. In a condition of insulin resistance insulin fails to block FoxO6, resulting in continued gluconeogenesis even upon feeding. Medications Certain medications increase the risk of hyperglycemia, including: corticosteroids, octreotide, beta blockers, epinephrine, thiazide diuretics, statins, niacin, pentamidine, protease inhibitors, L-asparaginase, and antipsychotics. The acute administration of stimulants such as amphetamines typically produces hyperglycemia; chronic use, however, produces hypoglycemia. Some of the newer psychiatric medications, such as Zyprexa (Olanzapine) and Cymbalta (Duloxetine), can also cause significant hyperglycemia. Thiazides are used to treat type 2 diabetes but it also causes severe hyperglycemia. Stress A high proportion of patients suffering an acute stress such as stroke or myocardial infarction may develop hyperglycemia, even in the absence of a<unk>  of diabetes. (Or perhaps stroke or myocardial infarction was caused by hyperglycemia and undiagnosed diabetes.) Human and animal studies suggest that this is not benign, and that stress-induced hyperglycemia is associated with a high risk of mortality after both stroke and myocardial infarction. Somatostatinomas and aldosteronoma-induced hypokalemia can cause hyperglycemia but usually disappears after the removal of the tumour. Stress causes hyperglycaemia via several mechanisms, including through metabolic and hormonal changes, and via increased proinflammatory cytokines that interrupt carbohydrate metabolism, leading to excessive glucose production and reduced uptake in tissues, can cause hyperglycemia. Hormones such as the growth hormone, glucagon, cortisol and catecholamines, can cause hyperglycemia when they are present in the body in excess amounts.
diagnosis of Diabetic ketoacidosis
complications of Diabetic ketoacidosis
medical cause of Cardiogenic shock
medical cause of Hyperthermia
symptom of Diabetic ketoacidosis
symptom of Syndrome of inappropriate antidiuretic hormone secretion
symptoms of Toxic shock syndrome
medical cause of Hypoglycemia