High levels of cortisol in your body can result in Cushing syndrome. Left untreated, Cushing syndrome can cause distressing symptoms and lead to serious health complications. Fortunately, tests can help determine the cause of high cortisol levels, which can guide treatment

Cushing syndrome, also known as hypercortisolism, occurs when you have higher-than-normal levels of cortisol in your body for a significant duration of time. Cortisol is a hormone made by your adrenal glands, two small glands located next to the kidneys. You can have high levels of cortisol if your adrenal glands overproduce it, or if you take cortisol-like medications (glucocorticoids) at high doses for a long time to treat another condition. The high cortisol levels can cause various symptoms and possible health complications.

In normal amounts, cortisol helps your body maintain blood pressure and blood sugar level, reduce inflammation, and regulate salt balance, among other functions. Cortisol is also directly connected to the body's stress response. Your body releases cortisol to help you deal with stressful situations.

Cushing syndrome due to your own body making too much cortisol (rather than taking too much) affects about three times as many women as men, and is most common in people ages 20 to 50. Cushing syndrome is considered rare, but the actual number of people who have it is unknown since some go undiagnosed.

"In Cushing syndrome, there are clinical signs that indicate your body has too much cortisol," explained Dr. Lisa Nachtigall, clinical director of the Neuroendocrine & Pituitary Tumor Clinical Center at Massachusetts General Hospital and associate professor of medicine at Harvard Medical School. "Once high cortisol levels are established, the next step is to figure out why that is happening."

The most common cause of Cushing syndrome is long-term use of glucocorticoids. Glucocorticoids are steroids used to treat a variety of conditions including asthma, cancer, inflammatory bowel disease, lupus, joint pain, and rheumatoid arthritis. They are also used to prevent transplant rejection. Examples of glucocorticoids are cortisone, prednisone, dexamethasone, and prednisolone.

Less often, Cushing syndrome occurs when the body makes too much cortisol. This is usually caused by a tumor (typically noncancerous) in the pituitary gland. Located at the base of your brain, the pituitary gland produces a hormone called adrenocorticotropic hormone (ACTH) that normally instructs the adrenal glands to make cortisol. A tumor can spur the pituitary gland to produce too much ACTH, which in turn causes the adrenal glands to produce too much cortisol. This form of Cushing syndrome is called Cushing disease.

In other cases, tumors in other organs can produce ACTH and lead to Cushing syndrome. Finally, the adrenal glands themselves can develop tumors that overproduce cortisol and can lead to Cushing syndrome.

Symptoms of Cushing syndrome include:

Left untreated, Cushing syndrome increases the risk of hypertension, diabetes, skeletal fractures, blood clots, heart attack, stroke, and increased risk of infections.

Because symptoms of Cushing syndrome can mimic many other conditions, diagnosis can be challenging.

Dr. Nachtigall points out that many people have symptoms of Cushing syndrome for years before they are diagnosed. "Unfortunately, Cushing syndrome isn't easy to diagnose," she says, "which can be very frustrating and overwhelming for patients."

Diagnosing Cushing syndrome is usually straightforward in people who are taking glucocorticoids. For others, tests used for diagnosis include:

Once your doctor diagnoses Cushing syndrome, the next step it to determine why it has happened. Knowing the cause of high cortisol levels guides the treatment.

If you take glucocorticoid medication, that's likely the cause of your Cushing syndrome. If Cushing syndrome is caused by the body's overproduction of cortisol, and after the high levels of cortisol have been definitively confirmed, the following tests can help pinpoint the specific reason:

Without treatment, Cushing syndrome can be life-threatening.

If Cushing syndrome is caused by glucocorticoids you are taking to treat another medical condition, you may be able to work with your doctor to gradually and carefully reduce your dose.

If a tumor is causing the disorder, you may need surgery to remove it. Medical therapies such as cortisol-blocking drugs may also be needed.

Dr. Nachtigall coauthored a research study on Cushing syndrome, which found that about 10% of people with Cushing syndrome develop an autoimmune disease after they are surgically treated and in remission. Some people have problems with memory and mood afterward as well. These problems may require additional medical therapy, says Dr. Nachtigall, but most symptoms improve after treatment.

Cushing syndrome may come back, even years later. Being aware of the symptoms of Cushing syndrome, and getting treated early, can help prevent long-term effects.

If you have Cushing syndrome, good lifestyle habits are key to avoiding complications. Having a healthy diet and getting regular exercise are essential, says Dr. Nachtigall.

Blood pressure can be high in people with Cushing syndrome; checking blood pressure and taking blood pressure-lowering medication if required can help. Cushing syndrome also increases the risk of osteoporosis. Maintaining bone strength through exercise and a healthy diet with adequate calcium and vitamin D intake, and making efforts to prevent falls (which can lead to fractures) are also important.

Source: Harvard Health Publishing

Marketed as a natural remedy for an enlarged prostate, saw palmetto is a top-selling dietary supplement. It's extracted from berries that grow on saw palmetto palm trees, which are native to the southeastern United States.

By one estimate, more than a third of all US adults who take supplements use saw palmetto specifically. Some evidence suggests that saw palmetto has anti-inflammatory properties, and its use as folk medicine dates back over a century.

But experts at Harvard say men should view its supposed benefits for prostate health skeptically. "Saw palmetto is unlikely to harm you, but it probably won't provide any major benefits either," says Dr. Heidi Rayala, an assistant professor of urology at Harvard Medical School and Beth Israel Deaconess Medical Center.

It's common for men to develop an enlarged prostate, or benign prostatic hyperplasia (BPH), when they get older. BPH impedes urinary flow through the urethra, causing obstructive symptoms that can worsen with time.

Just how saw palmetto might act on the prostate to improve symptoms isn't entirely clear, however. Some evidence suggest it mimics the effects of certain drugs used for treating BPH, including 5-alpha reductase inhibitors such as finasteride (Proscar), which shrink the prostate gland.

In the US, no herbal supplement is approved as BPH treatment. The American Urological Association cautions that studies backing saw palmetto for treating enlarged prostates have numerous flaws, including short durations and a lack of placebo controls. Most of the supporting evidence comes from small studies paid for by companies that sell dietary supplements.

The best-conducted research shows no benefits from saw palmetto for BPH. During one study, 225 men with moderate to severe BPH were treated with either a placebo or 160 milligrams (mg) of saw palmetto, taken twice daily for a year. The investigators detected no difference in outcomes, but they also acknowledged that doses tested in the study may have been too low to produce measurable effects.

So, during a larger subsequent study, researchers tested higher doses of saw palmetto ranging up to 320 mg given three times a day. Nearly 370 men ages 45 and older were randomized to treatment or placebo groups. After year and a half, men in both groups reported feeling either no worse or a little better. Remarkably, 40% of the placebo-treated men said symptoms had improved, suggesting the simple act of taking a pill could have something to do with the supplement's perceived benefits.

Dr. Michael Barry, a professor of medicine at Harvard Medical School, led the study. He urges men to consult with their doctors before trying saw palmetto, mainly to rule out other potential causes of urinary obstruction, which can include bladder or prostate cancer. And saw palmetto may interfere with the blood's clotting ability, making it risky for men who take blood thinners.

The latest evidence on saw palmetto and BPH comes from a Cochrane Review of 27 placebo-controlled studies enrolling a combined 4,656 participants. Results published in 2024 showed no improvement in urinary symptoms or quality of life from taking saw palmetto (alone or with other herbal supplements) over durations ranging up to 17 months.

"If the ingredients in these herbal products worked well for urinary symptoms, drug companies would have already had them approved by the FDA as a medicine that insurance companies would have to cover," Dr. Rayala said. "It's okay to take them, but just be cautious about spending too much of your own money on these alternatives."

"It is easy to understand why so many find taking a naturally occurring supplement for treating urinary difficulties in middle age appealing," said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of the Harvard Medical School Guide to Prostate Diseases. "However, evidence of effectiveness with saw palmetto is lacking, and its use for BPH and other common urinary symptoms without a full evaluation of the potential cause should be discouraged."

Harvard Health Publishing