Hypoglycemia Unawareness

Impaired awareness of hypoglycemia (IAH), often called hypoglycemia unawareness, is a reduced ability to recognize the usual early warning symptoms of low glucose. The person may have a glucose value below 4.0 mmol/L and feel normal, or notice symptoms only after cognitive function is already affected. This is dangerous because autonomic symptoms normally provide time to act. Tremor, sweating, hunger, palpitations, and anxiety are the body’s alarm system. With IAH, that alarm becomes delayed or quiet. The first obvious sign may instead be neuroglycopenia: confusion, irritability, unusual behaviour, blurred vision, impaired coordination, drowsiness, seizure, or loss of consciousness. Hypoglycemia is classified by severity: - Level 1: glucose below 4.0 mmol/L and at least 3.0 mmol/L. - Level 2: glucose below 3.0 mmol/L. This is clinically significant hypoglycemia and should prompt review of the treatment plan. - Level 3: altered mental or physical status requiring assistance from another person. A glucose number is not required to define level 3. A person with IAH is not “tolerating” low glucose safely. They are losing the warning time that would normally prevent severe hypoglycemia.