Cortisol is a hormone produced by the adrenal glands that plays a key role in regulating metabolism, immune function, and the body’s response to stress. Often called the “stress hormone,” cortisol naturally rises and falls throughout the day and increases during physical or emotional stress.

When levels remain elevated for too long, however, it can quietly take a toll on health.

Chronically high cortisol can affect multiple systems in the body. Common effects include weight gain, particularly around the abdomen, elevated blood pressure, and disrupted sleep.

Excess cortisol may also weaken the immune system, making people more prone to frequent infections, and contribute to anxiety, irritability, and mood changes.

Over time, persistently elevated cortisol levels can raise the risk of more serious health conditions, including Type 2 diabetes, osteoporosis, and cardiovascular disease. Identifying the signs early and taking steps to manage stress can help protect long-term health.

Dr. Karan Rajan, a surgeon and author of This Book May Save Your Life, says high cortisol levels may show up in subtle ways, including feeling “tired but wired” at night, trouble sleeping, unexplained weight gain, frequent colds, anxiety or irritability, and increased cravings or digestive issues.at

Rajan notes that cortisol levels can be measured through blood, urine, or saliva tests. If testing confirms that levels are abnormally high, lifestyle changes can often help bring them back into balance.

· Eat more fiber. Fiber helps regulate blood sugar, which is often disrupted by cortisol spikes. It also supports a healthy gut microbiome, reduces inflammation, and promotes fullness, helping to prevent stress-related overeating.

· Improve sleep quality. Rajan says even small improvements in sleep habits can lower cortisol levels. Practicing good sleep hygiene, such as keeping a consistent bedtime and limiting screen time before bed, can make a difference. The Sleep Foundation has more tips on sleep hygiene.

· Limit caffeine and alcohol. Excessive intake of either can stimulate cortisol production and keep levels elevated.

· Make meaningful social connections. Studies consistently show that healthy social interaction lowers stress hormones and supports emotional well-being.