The excess or deficiency of hormones has a harmful effect on our body. Feedback mechanism makes sure that hormones are secreted in precise quantities and at right time.

For example Diabetes is due to deficiency of Insulin hormone secreted by the Pancreas that is responsible to lower/control the blood sugar levels. This regulation of hormone secretion is achieved by a feedback mechanism. This system will switch off the machinery (hormone synthesis) when it is sufficient in the body and will switch it on only when the concentration is less.

Explanation: Insulin is the hormone secreted by the pancreas to maintain blood sugar level. If it is not secreted in the proper amount, the blood sugar level rises to cause harmful effects. Hence it is important that the hormone should be present in a correct amount for proper function.