Hypersecretion is an excessive secretion of a hormone by a gland. A hormone can undergo either primary hypersecretion (the gland is secreting too much of the hormone on its own) or secondary hypersecretion (there is excessive stimulation of the gland by its tropic hormone). One of the most common causes of primary or secondary hypersecretion is the presence of a hormone-secreting endocrine-cell tumor. These tumors tend to produce their hormones continually at a high rate, even in the absence of stimulation.
For the diagnosis of primary versus secondary hypersecretion, the concentrations of the hormone and, if relevant, its tropic hormone are measured. If both concentrations are elevated, then the hypersecretion is secondary. If the hypersecretion is primary, there will be a decreased concentration of the tropic hormone because of negative feedback by the high concentration of the hormone being hypersecreted. As with hyposecretion, tertiary hypersecretion of the peripheral endocrine gland can occur when there exists a three-step sequence of hormones. When an endocrine tumor is the cause of hypersecretion, it can often be removed surgically or destroyed with radiation if the tumor is confined to a small area. In many cases, hypersecretion can also be blocked by drugs that inhibit the hormone’s synthesis. Alternatively, the situation can be treated with drugs that do not alter the hormone’s secretion but instead block the hormone’s actions on its target cells.