The causes of low blood sugar vary depending on the situation and the individual. Low blood sugar, also known as hypoglycemia, is defined as a blood sugar level of less than 70 mg per deciliter. When left untreated for a long period, it can be very harmful.
Insulin
Insulin is a hormone that under normal circumstances regulates blood sugar levels, allowing the body to obtain and use energy. But if the pancreas isn't working correctly, too much insulin may be released, causing low blood sugar. Insulinoma, a rare condition involving tumors in the pancreas, is one disease that can cause this, notes MedlinePlus. Low blood sugar also results if a diabetic takes too much insulin. Other causes of low blood sugar include hypothyroidism, Addison's disease, liver disease, and hypopituitarism, according to Mosby's Diagnostic and Laboratory Test Reference.
Medications
In addition to insulin, several other medications may cause low blood sugar, including beta blockers, antibiotics and antipsychotics. Examples of such medications are Bactrim, Haldol and quinine.
Sickness
Low blood sugar may result from various health conditions. Among them is brittle diabetes, in which an ineffective use of insulin results in alternating episodes of high and low blood sugar. Taber's Encyclopedic Medical Dictionary explains that this happens when insulin is not well-absorbed, when insulin requirements vary rapidly or when there is persistent psychological or physiological stress.
Cancer is another disease in which blood sugar may run low, since lack of appetite results in low food intake. Adrenal insufficiency may also cause low blood sugar. The adrenal hormone cortisol regulates glucose levels, so if the adrenal glands aren't working effectively, cortisol cannot do its job.
References
- MedlinePlus: Hypoglycemia
- MedlinePlus: Drug-induced Hypoglycemia
- Mosby's Diagnostic and Laboratory Test Reference; Kathleen Pagana; 2003
- MedlinePlus Medical Encyclopedia: Insulinoma
- Taber's Cyclopedic Medical Dictionary; Donald Venes; 2005
- National Endocrine and Metabolic Information Service: Adrenal Insufficiency and Addison's Disease
