Cortisol, often called the “stress hormone,” is a steroid hormone produced by your adrenal glands, which are small glands located on top of each kidney. This hormone plays a role in the body’s response to stress and affects nearly every organ and tissue. Monitoring cortisol levels can offer insights into various bodily functions.
Understanding Cortisol Measurement
Cortisol levels are monitored due to their widespread influence on bodily systems and connection to the stress response. Cortisol helps regulate metabolism, blood sugar levels, blood pressure, and immune function. It is released as part of the “fight or flight” response, preparing the body for perceived threats.
Consistent or abnormal cortisol levels can suggest underlying issues. For instance, chronically elevated cortisol might be associated with conditions such as Cushing’s syndrome, characterized by symptoms like rapid weight gain, high blood pressure, and muscle weakness. Conversely, abnormally low levels could indicate adrenal insufficiency, like Addison’s disease, which can lead to fatigue, low blood pressure, and dizziness. Measuring cortisol helps assess adrenal gland function.
Types of Monitors and Their Function
Cortisol can be measured through various methods, each offering different insights into its levels. Saliva-based monitors are a common at-home option. They work by collecting saliva samples, often at specific times throughout the day, which are then analyzed to determine the amount of free, biologically active cortisol. Salivary cortisol levels reflect free cortisol in the blood, making them a convenient and non-invasive way to track daily rhythms.
Wearable devices represent an emerging area in cortisol monitoring. While many current wearables indirectly track stress through physiological indicators like heart rate variability or skin conductance, direct cortisol sensing wearables are being developed. For example, some experimental patches can wick up sweat and assess cortisol levels in seconds, detecting charged ions that are blocked by cortisol. Other research explores microdialysis probes inserted just under the skin to continuously measure hormone levels over 24 to 48 hours, with the fluid later sent for analysis. These technologies aim to provide real-time or continuous data without requiring traditional blood draws.
Traditional blood and urine tests remain standard clinical methods for measuring cortisol. Blood tests provide a snapshot of cortisol levels at a specific moment, often taken in the morning when levels are highest and again in the afternoon. Urine tests, particularly 24-hour collections, measure the total amount of cortisol excreted over a full day, offering a comprehensive view of overall cortisol production rather than a single point in time. These laboratory-based methods offer high accuracy but generally do not provide continuous monitoring.
Interpreting Results and Important Considerations
Interpreting cortisol levels requires understanding their natural fluctuations. Cortisol levels follow a circadian rhythm, peaking in the early morning (between 6 AM and 8 AM) and gradually declining throughout the day, reaching their lowest point around midnight. This pattern can shift with changes in sleep-wake cycles, such as for night-shift workers.
At-home cortisol monitors offer personal insight into these daily patterns but are not intended as diagnostic tools. Factors like physical activity, pregnancy, serious illness, and certain medications, including corticosteroids, can influence cortisol readings. Results from at-home tests should always be discussed with a healthcare professional, who can interpret them within the context of an individual’s overall health history and symptoms.