Serum Cortisol

Function

Cortisol is often referred to as the 'stress hormone' and is a vital steroid hormone produced by the adrenal glands. It is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Its primary functions include regulating metabolism, reducing inflammation, assisting with memory formulation, and controlling the salt and water balance. It also plays a critical role in the 'fight or flight' response, increasing blood glucose to provide immediate energy during stressful situations.

Why it is Ordered

This test is primarily ordered when a healthcare provider suspects an overproduction or underproduction of cortisol. Symptoms of overproduction (Cushing's Syndrome) include rapid weight gain in the face and torso, high blood pressure, and skin changes. Symptoms of underproduction (Addison’s Disease) include fatigue, muscle weakness, loss of appetite, and low blood pressure. It is also used to monitor individuals being treated for adrenal or pituitary disorders.

Associated Conditions

• Cushing's Syndrome: Caused by excess cortisol, often due to an adrenal tumor or a pituitary tumor (Cushing’s Disease).
• Addison’s Disease: Primary adrenal insufficiency where the glands do not produce enough cortisol.
• Secondary Adrenal Insufficiency: A problem with the pituitary gland's ability to signal the adrenals.
• Ectopic ACTH Syndrome: Tumors outside the HPA axis producing ACTH.