​​​​​​​​​Of all your hormones, cortisol may be one of the most misunderstood. If you're tuned in to TikTok or Instagram, you'll see cortisol getting blamed for weight gain, sleep problems, high stress and more. 

But you also need cortisol ​​to regulate your blood pressure, control your blood sugar and boost your immune system.

So, what's the real deal with cortisol and the impact it has on your body? Jennifer Wittwer, MD, an endocrinologist with The Christ Hospital Diabetes & Endocrine Center, explains what this hormone is and the role it plays in your body.

What is cortisol?

Cortisol is a steroid hormone produced by the adrenal glands that sit on top of your kidneys. It follows a daily cycle. So, your cortisol level is higher in the morning, and it declines during the day.

Cortisol plays a role in almost every organ system. You need it to:

• Control your metabolism (how your body processes carbohydrates, fats and proteins)
  
• Control your sleep-wake cycle
• Manage your body's stress response
• Reduce inflammation
• Regulate your blood sugar
• Regulate your blood pressure

​“Cortisol is the hormone that's responsible for waking you up in the morning. And we need it to feel refreshed and to give us energy during the day," Dr. Wittwer says. “It's also beneficial during stressful periods in our lives. For example, when we're sick, our cortisol levels naturally rise to ignite our immune system and help us fight off invaders from an infection."

What causes high cortisol levels?

It's rare for your cortisol level to stay elevated long-term. If this happens, you could have a condition called Cushing's syndrome. An elevated cortisol level is usually due to:

• Adrenal gland tumors that produce excess cortisol
  
• Long-term use of corticosteroid medication like prednisone
• Pituitary tumors , and rarely ectopic (in an abnormal place) tumors, that produce adrenocorticotropic hormone (ACTH) that trigger more cortisol production

Stress and your body's fight-or-flight response in threatening situations can also increase your cortisol level. Your heart rate and breathing speed up during these episodes and usually return to typical levels quickly.

But if you have chronic stress, your cortisol level can stay elevated. Poor, long-term sleeping and eating habits can also raise your cortisol.

What happens when cortisol levels are high?

High cortisol levels have been linked to several health conditions, including:

• Blood sugar spikes
  
• Easy bruising
• Metabolic syndrome, which raises your risk of cardiovascular disease, diabetes and stroke
• Muscle weakness
• Osteoporosis
• Weight gain due to slow metabolism

But it's important to remember that short spurts of elevated cortisol are your body's proper response to stressors, Dr. Wittwer says.  

“Cortisol itself may not be the issue. Instead, it may be other factors that impact cortisol levels that contribute to these other problems," she says. “It's difficult to sift out whether it's the chicken or the egg. Oftentimes, this is your body's response to some sort of stressor that's coming from the outside that causes more cortisol production."

Does a high cortisol level really cause weight gain?

Weight gain is often associated with high cortisol levels. As you age, you're more likely to gain weight around your abdomen. But cortisol isn't necessarily to blame, Dr. Wittwer says. Instead, those extra pounds can be due to a combination of changes, especially in females.

“In females, estrogen helps regulate where fat goes in the body. But estrogen levels drop during menopause, and we also lose the muscle mass that helps drive our metabolism," she says. “Having more fat deposits and less muscle is very stressful on the body. That can raise your cortisol level instead of your cortisol level driving weight gain on its own."

 Can you regulate your cortisol level?

Dr. Wittwer says adopting healthy lifestyle behaviors is the best way to regulate your cortisol level. She suggests following the Life's Essential 8 plan from the American Heart Association. These behaviors can help you manage your cortisol:

• Control cholesterol. Lower your level of non-HDL cholesterol. High levels can lead to heart disease.
• Eat a healthy diet. Eat fruits, vegetables, lean proteins, nuts and seeds. Cook with olive or canola oil.
• Exercise. Get 150 minutes of moderate or 75 minutes of intense exercise every week.
• Get plenty of sleep. Adults need between seven and nine hours of sleep per night. Depending on age, children need between 10 and 16 hours of nightly sleep.
• Lower blood pressure. Keep your blood pressure below 120/80 mm Hg. Higher levels can increase your risk of heart problems.
• Maintain a healthy weight. Talk with your healthcare provider about a healthy weight for you.
• Manage blood sugar. Limit your sugar intake. If you have pre-diabetes or diabetes, track your A1c.
• Quit tobacco. Give up traditional cigarettes, e-cigarettes and vaping.

Overall, Dr. Wittwer says managing and maintaining a healthy cortisol level is fundamental to regulating your general well-being.

“Cortisol is a very necessary hormone. We need it to survive. But it's a very complicated hormone that is influenced by a lot of different factors," she says. “How you live your life helps to control your cortisol levels. There's no way around it—focusing on eating healthfully, exercising and sleeping are all important to regulating your cortisol."