Cortisol is often framed online as a villain, but doctors say the hormone is essential to survival and works as part of the body’s stress response. Produced by the adrenal glands above the kidneys, cortisol helps regulate processes that include inflammation, the immune system, metabolism and blood pressure, among other functions. It also fluctuates naturally: levels rise in the morning after a person wakes and fall at night before sleep, and cortisol can rise when someone is sick or otherwise under stress, doctors said.
Dr. Roberto Salvatori, an endocrinologist at Johns Hopkins University, described the hormone as closely tied to the body’s moment-to-moment state. “Our cortisol level is regulated by the minute,” Salvatori said. Because cortisol is so responsive, doctors said people should not assume that a single data point explains what their bodies are doing or what they need.
Doctors said true cortisol disorders are relatively rare, and they typically diagnose different conditions depending on whether cortisol is chronically too low or too high. If cortisol levels are chronically low, clinicians would diagnose adrenal insufficiency, including Addison’s disease, an autoimmune condition in which the immune system attacks the adrenal gland. By contrast, people with Cushing’s syndrome have cortisol levels that are too high; doctors said tumors are among the causes and are usually benign, located in the adrenal or pituitary glands.
Dr. Katie Guttenberg, an endocrinologist at UTHealth Houston, said cortisol testing requires clinical nuance. “There’s a lot of nuance to interpreting cortisol and that’s what makes me a little bit nervous about patients getting cortisol testing for themselves without having some kind of physician oversight,” Guttenberg said. She added that a one-off cortisol blood test is unlikely to provide useful information for most people, and she said it could increase unnecessary stress and lead to medical follow-ups that are not needed.
Guttenberg also warned that some common medication uses can affect cortisol readings. She said women on birth control can have falsely high cortisol blood results because of how the medicine works in the body. She and other endocrinologists said these issues are part of why cortisol testing should be guided by a physician rather than pursued as an isolated self-diagnostic step.
Endocrinologists also said there is no proven over-the-counter approach to treat high or low cortisol. Dr. James Findling, an endocrinologist with the Medical College of Wisconsin, said there are no proven treatments in supplements marketed as lowering cortisol, despite claims that products such as ashwagandha and magnesium can help. Findling said people should also be cautious because unregulated supplements are not always clear in what they contain, and “They’re not innocuous,” he warned.
Even in patients who do have Cushing’s syndrome, doctors said medication must be carefully dosed because over-correction can drive cortisol levels too low and create other health problems. Doctors also noted a related condition called pseudo Cushing’s syndrome, which can cause some of the same physical effects without a tumor; they said it can be associated with alcoholism and other chronic issues and is generally treated by addressing the underlying cause.
Doctors said that for many people, the practical next step is not a cortisol-focused supplement or a self-ordered lab test, but medical conversation if symptoms are persistent or concerning. They said stress is highly subjective, and they acknowledged that some patients with cortisol-related conditions can go unheard and undiagnosed. But their advice for most people was consistent: talk to a doctor if you are concerned, and otherwise return to stress management fundamentals such as eating well, getting enough sleep, moving the body and considering therapy.
They also pointed out that research continues into how treatments might help people with high cortisol. Findling said his work includes studying the condition and that it could potentially help diabetics who are taking multiple drugs better control their blood sugar. In the meantime, Findling said there is “Nothing new about any of that,” referring to the basics of stress management.