The hormones are released in very small amounts into the bloodstream and then travel to parts of the body referred to as target organs to perform a specific job. Aim for serum IGF-I levels in the middle of the normal range appropriate for age and sex, unless side effects are significant. Stopping treatment Adult growth hormone deficiency symptoms resolve this problem. Neurocognitive function in adults with growth hormone deficiency. A pulmonary function test may reveal dimished lung respiratory muscle capacity.