摘要
为调节自身状态以适应环境变化，激素的浓度可以变化很大。它们的浓度经常通过负反馈机制进行调节，这种机制导致系统调控的严密性。在诊断内分泌疾病时，我们常常遇到的一个难题是即使患者具有明显疾病时，其激素水平仍可能处于公开发表的“参考值范围”内。这是因为激素的浓度可能由于其他外界因素而变化，而正常值范围没有将这些考虑在内。因此，由于所测定的激素水平保持在正常范围之内，功能亢进可能被漏诊。例如，在原发性甲状旁腺功能亢进症中，尽管存在高血钙，甲状旁腺激素的浓度可能在参考值范围之内，虽然理论上后者应该受到抑制；这个事实使我们不能确定原发性甲状旁腺功能亢进症的诊断。同样，库欣病患者的皮质醇和促肾上腺皮质激素也可能均在参考值范围之内。
Hormone concentrations can vary widely in an attempt to regulate for changes in the environment. Their levels are often regulated by negative feedback, which usually results in tight control of a system. One difficulty in diagnosing endocrine disease is that hormone levels may be in the published ‘reference range＇, even in patients with significant disease. This is because the concentration of hormones should vary depending on other, extraneous factors, and the normal range does not take account of this. Thus, hyperfunction can be missed because the measured levels remain within the reference range. In primary hyperparathyroidism, for example, the concentration of parathyroid hormone may be within the reference range despite high calcium levels, though it should be suppressed; the fact that it is not confirms primary hyperparathyroidism. In Cushing＇s disease, cortisol and adrenocorticotrophic hormone may both be within the reference range.
