What is Cortisol?
A cortisol test may be ordered when a patient has symptoms that suggest Cushing's syndrome (obesity, muscle wasting, and muscle weakness) or Addison's disease (weakness, fatigue, increased pigmentation, among others). In normal people, cortisol levels are very low at bedtime and at their highest just after waking. This pattern will change if a person works irregular shifts (such as the night shift) and sleeps at different times of the day. Cortisol blood tests may be drawn at about 8 am, when cortisol should be at its peak, and again at about 4 pm, when the level should have dropped. Sometimes a resting sample will be obtained late in the evening to measure cortisol when it should be at its lowest concentration in the blood.
Purpose of Test
Quantitative determination of Cortisol levels in human serum
Test of Result Interpretation
AM 6.7-22.6 PM < 10 microgram/dL.
No preparation required.