There are two common emergency conditions in diabetes namely, Ketoacidosis and hypoglycemic coma.
Ketoacidosis: Diabetic Ketoacidosis is a dangerous complication of diabetes triggered by lack of insulin in the body. In the absence of insulin, fat reserves in the body are broken down for energy resulting in toxic byproducts called ketones.
If blood glucose levels are consistently over 240mg/dl and do not come down then regular urine tests for ketones is advisable.
If the blood glucose levels are above 300mg/dl or urine test is positive for ketones at any stage, a doctor should be consulted immediately and if advised, the patient should be hospitalized.
Hypoglycemic coma : Blood glucose levels below 50mg/dl can lead to severe hypoglycemia, which if not checked immediately can progress to hypoglycemic coma. The blood glucose level in this condition is below 30mg/dl. The patient should be hospitalized immediately.