Cortisol is a stress-response hormone made by the adrenal cortex. It follows a daily rhythm (highest in the morning, lowest around midnight) and is measured in blood, late-night saliva, or 24-hour urine to evaluate cortisol excess or deficiency. (MedlinePlus)
Cortisol is a steroid hormone made by your adrenal glands. It is often called the main stress hormone because it rises when your body needs to respond to pressure, but it does much more than that.
It helps control blood sugar, blood pressure, metabolism, and the sleep and wake rhythm. Levels follow a daily pattern, highest in the early morning and lowest around midnight.
Cortisol helps you see whether your stress response and adrenal glands are working normally. Persistently high levels can point to Cushing's syndrome, chronic stress, or certain medications, and may go along with weight gain, high blood pressure, and poor sleep.
Low cortisol can signal adrenal insufficiency (Addison's disease) or a pituitary problem, and may cause fatigue, low blood pressure, and weight loss. Because cortisol changes through the day, the timing of the draw matters a lot.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
| When | Adult serum range (SI) |
| Morning, 7 to 9am | ~140 to 690 nmol/L |
| Afternoon, around 4pm | ~80 to 330 nmol/L |
| Late evening (low point) | often below 140 nmol/L |
Ranges are guidance only and depend strongly on time of day and the assay used. Always read your result against your own lab's reference interval, in line with DGKL practice.
Time of day has a large effect, so morning draws are standard. Stress, acute illness, pregnancy, and oestrogen containing pills raise levels by increasing binding protein. Steroid medication, including inhaled or topical forms, can suppress results. Shift work and poor sleep can shift the daily pattern.
Often read alongside ACTH, and with TSH and glucose when fatigue or metabolic symptoms are being worked up.
One annual membership, 100+ biomarkers, every result explained in plain language with a personalized action plan and concierge guidance.
