Which symptom might indicate an adverse reaction to insulin?

An adverse reaction to insulin can manifest in various ways, and one of the critical symptoms to recognize is a rapid heart rate and sweating. These symptoms can indicate hypoglycemia, which occurs when blood sugar levels drop too low as a result of insulin administration. The body responds to low blood sugar by releasing adrenaline, which can lead to symptoms such as increased heart rate, sweating, trembling, and anxiety.

In contrast, increased appetite and improved concentration do not signify an adverse reaction; rather, they could be responses to normalized blood sugar levels, while weight reduction might suggest that blood sugar control has not been effectively achieved, leading to a different set of concerns unrelated to an immediate adverse reaction. Understanding these distinctions is vital for monitoring and ensuring safe insulin administration in patients.