Cortisol, PM (Afternoon/Evening)
Cortisol is your body's main stress hormone, made by the adrenal glands. This measurement is taken in the afternoon or evening, when levels are naturally at their lowest.
Cortisol normally follows a daily rhythm: high in the early morning to help you wake and get going, then falling steadily to a low point around bedtime. Checking an afternoon or evening level helps show whether that rhythm is intact. A healthy nighttime dip supports restful sleep and balanced metabolism, blood pressure, and blood sugar.
An afternoon or evening cortisol that stays high may suggest the normal daily decline is blunted, which can happen with significant stress, illness, disrupted sleep, or certain adrenal or pituitary conditions. A late-night value is sometimes used as part of screening for cortisol excess (Cushing's syndrome), but a single reading is not diagnostic and timing matters a great deal.
A low evening cortisol is often expected, since this is the natural low point of the day, so it is usually less concerning than a low morning value.
There is no single 'ideal' number; healthy evening cortisol is normally much lower than the morning peak. Because ranges depend heavily on the exact time of collection and the lab's method, interpret your result against the reference range on your report and with your clinician.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.