glucose levels occurs. According to the U.S. National Institutes of Health (NIH), a blood glucose level below 70 mg/dL (3.9 mmol/L) at the time of symptoms followed by relief after eating confirms a diagnosis for reactive hypoglycemia. Signs and symptoms Symptoms vary according to individuals' hydration level and sensitivity to the rate and/or magnitude of decline of their blood glucose concentration. A crash is usually felt within four hours of heavy carbohydrate consumption. Along with the symptoms of hypoglycemia, symptoms of reactive hypoglycemia include: double vision or blurry vision unclear thinking brain fog insomnia heart palpitation or fibrillation fatigue dizziness light-headedness sweating headaches depression nervousness muscle twitches irritability tremors flushing craving sweets increased appetite rhinitis nausea, vomiting panic attack numbness/coldness in the extremities confusion irrationality hot flashes bad temper paleness anxiety trouble talking cold hands disorientation the need to sleep or 'crash' The majority of these symptoms, often correlated with feelings of hunger, mimic the effect of inadequate sugar intake as the biology of a crash is similar in itself to the body's response to low blood sugar levels following periods of glucose deficiency. Causes The NIH states: "The causes of most cases of reactive hypoglycemia are still open to debate. Some researchers suggest that certain people may be more sensitive to the body’s normal release of the hormone epinephrine, which causes many of the symptoms of hypoglycemia. Others believe deficiencies in glucagon secretion might lead to reactive hypoglycemia. Several other hormones are responsible for modulating the body's response to insulin, including cortisol, growth hormone and sex hormones. Untreated or under-treated hormonal disorders such as adrenal insufficiency (see also Addison's disease) or growth hormone deficiency can therefore sometimes cause insulin hypersensitivity, and reactive hypoglycemia. Stomach bypass surgery or hereditary fructose intolerance are believed to be causes, albeit uncommon, of reactive hypoglycemia. Myo-inositol or 1D-chiro-inositol withdrawal can cause temporary reactive hypoglycemia. There are several kinds of reactive hypoglycemia: Alimentary hypoglycemia (consequence of dumping syndrome; it occurs in about 15% of people who have had stomach surgery) Hormonal hypoglycemia (e.g., hypothyroidism) Helicobacter pylori-induced gastritis (some reports suggest this bacteria may contribute to the occurrence of reactive hypoglycemia) Congenital enzyme deficiencies (hereditary fructose intolerance, galactosemia, and leucine sensitivity of childhood) Late hypoglycemia (occult diabetes; characterized by a delay in early insulin release from pancreatic beta-cells, resulting in initial exaggeration of hyperglycemia during a glucose tolerance test) "Idiopathic reactive hypoglycemia" is a term no