Cortisol (serum, random or 8 AM)

What this test is

Cortisol is a hormone made by your adrenal glands. It helps you handle stress. It also helps keep your energy steady. This blood test checks for real problems, like very low cortisol or very high cortisol. It is not a good test for plain tiredness. Cortisol goes up and down all day. One number, taken at a random time, can be misleading. Tell your doctor if you have new weight loss, dizzy spells when standing, salt cravings, or skin that is getting darker. Those signs point to a real problem worth testing for.