Adrenal gland function is tested by analyzing blood or urine to measure the presence of four hormones: Aldosterone, cortisol, 18-hydroxycortisol and DHEA-S. This analysis helps diagnose adrenal abnormalities and diseases, according to HealthCommunities.com.
Aldosterone regulates salt, potassium, and water balance and controls blood pressure. Aldosterone is measured in both the blood and urine. Cortisol controls the metabolism, regulates the immune system and regulates the body's response to stress. Too much cortisol may indicate Cushing's syndrome and too little cortisol may indicate Addison's disease. Free cortisol in both the blood and urine are measured in adrenal tests, states HealthCommunities.com
18-Hydroxycortisol is a steroid and a byproduct of cortisol metabolism. Measuring blood levels of this hormone can determine the cause of hyperaldosteronism. DHEA-S is an androgen and precursor to testosterone. Too much of this hormone in women can cause male body characteristics, excessive hair growth, absence of menstruation and infertility, reports HealthVommunities.com
Fasting may be required before having blood drawn for adrenal gland function testing. Urine samples are collected over at prescribed time intervals over a 24-hour period to accurately measure urinary excretion of aldosterone, cortisol, and 18-hydroxycortisol, says HealthVommunities.com
Adrenal fatigue is a term referring to low adrenal production, however, hormonal fatigue is more likely caused by the thyroid, according to WebMD.