Have you been stressed out lately, gained weight, or learned your blood pressure or glucose levels have been elevated? If so, you've probably searched your symptoms online and may have come across "high cortisol levels" as a possible reason for what you're experiencing.

After all, it makes sense: High blood pressure, high blood sugar, sudden weight gain in the face and belly, thinning skin and stretch marks can all be symptoms of conditions linked to increased cortisol levels. But despite what you may see online, conditions related to cortisol are incredibly rare.

"Diabetes, high blood pressure and weight gain are all common ailments that patients experience, but it's very unlikely that a true medical condition causing abnormally high levels of cortisol is to blame," says Dr. Archana Sadhu, an endocrinologist at Houston Methodist.

In truth, cortisol rises and falls throughout the day, and outside stress can release cortisol into the body, which is why it's called the stress hormone. But that's when you start getting into a "gray area," according to Dr. Sadhu, and likely why many people attribute their symptoms to elevated levels of cortisol.

Cortisol plays a key part in our health, and knowing what it is, how it works and when to see a doctor are all important steps toward better health and education.

What is cortisol and what does it do?

Our bodies use hormones to communicate messages across body parts. Cortisol is a type of hormone produced by your adrenal glands, which sit atop each kidney, that helps us respond to stress. And it can communicate with nearly every organ system in the body.

"Cortisol is one of our 'fight or flight' hormones," says Dr. Sadhu. "It's the key mechanism for how ancient humans survived. If we saw something dangerous coming, we had to either fight them or run to survive. And cortisol is one of the key hormones that gets released during times of need and stress."

"So you can imagine why cortisol plays a key role in raising and maintaining our blood pressure, maintaining our blood glucose levels and maintaining the chemical balance in our blood — all in anticipation for that physical activity our bodies were designed to do," says Dr. Sadhu.

Besides regulating stress, however, cortisol influences many functions vital to our wellbeing, including:

• Metabolism
• Blood sugar levels
• Anti-inflammation
• Blood pressure
• Heart rate
• Circadian rhythm (sleep-wake cycle)
  
  

(Related: How to Boost Your Metabolism)

How does your body regulate cortisol levels?

"We have three glands that control the release of cortisol into the body, and it's a very exquisite system that has multiple influences to keep cortisol regulated," says Dr. Sadhu.

These glands are the adrenal glands, the hypothalamus and pituitary gland, the latter two of which are located in the brain. Each gland stimulates the other using different hormone signals to regulate cortisol in the blood.

Issues occur when the three glands fall out of balance.

What can affect your cortisol levels?

"Cortisol is unique in that the stress of everyday life can affect it, and that's where things begin to enter a gray area," says Dr. Sadhu. "Sleep is certainly known to affect cortisol levels. We know that if you don't get good sleep, your cortisol will go up, and you may have symptoms as a result of that."

As mentioned, cortisol plays a key role in the circadian rhythm — our bodies' "internal clock" that follows a 24-hour cycle in order to carry out essential functions. Cortisol, per Dr. Sadhu, peaks in the morning and drops in the evening.

"Cortisol, along with some other hormones, are what helps us wake up and get ready to start the day," says Dr Sadhu. "When this pattern is disrupted, cortisol is also affected.

"Anxiety, insomnia, obstructive sleep apnea, working night shifts and even life stress can all affect sleep and, thus, cortisol," she says. "But these kinds of disruptions to the circadian rhythm can be hard to measure and prove in terms of high circulating cortisol levels in the blood that can be medically treated. They're usually brief, in response to immediate stress, and are very different than a medical condition where cortisol's overproduced and circulating at high levels all the time."

It's true that cortisol plays a role in chronic stress, lack of sleep and anxiety — some might even share symptoms related to high cortisol as a condition. But Dr. Sadhu says it's unlikely for cortisol to be the underlying cause of many of these conditions.

(Related: 5 Ways Poor Sleep Affects the Body)

Cortisol can also be affected by corticosteroids, synthetic versions of cortisol, that are used to treat a variety of conditions, including:

• Autoimmune diseases
• Asthma
• Rheumatoid arthritis
• Inflammatory bowel disease
• Preventing organ rejection in transplant patients
  
  

Short-term usage of corticosteroids, like hydrocortisone to treat rashes or allergies, are unlikely to cause cortisol-related side effects. But when they are used long-term for any reason, Dr. Sadhu says, patients can develop complications. Patients are recommended to stay in contact with their doctor to monitor any potential side effects related to corticosteroid treatment that might mimic medical conditions that cause high cortisol.

(Related: Should You Be Following an Anti-Inflammatory Diet?)

What are symptoms of chronically high cortisol?

When your body is chronically exposed to too much cortisol — from medication or from a disease process — it's likely you may experience Cushing syndrome, a rare condition in which your body has too much circulating cortisol on a long-term basis.

Common signs and symptoms of Cushing syndrome include:

• Weight gain: Cushing syndrome has a very specific weight gain pattern focused on the face; the back of the neck and shoulders; and around the belly and abdomen.
• Thin skin and stretch marks: High cortisol can also cause skin proteins to break down, resulting in thin skin and, in combination with weight gain, large, often purple stretch marks called striae across the belly.
• Muscle loss and weakness: Cortisol breaks down protein, so high levels of cortisol can cause loss of muscle and weakness, especially in the arms and legs.
• High blood pressure: Cushing syndrome can cause fluid retention, thereby increasing blood pressure and causing hypertension (high blood pressure).
• High blood sugar: Cortisol also regulates blood sugar, so too much cortisol can cause chronic high blood sugar, or even diabetes, in Cushing syndrome patients.
  
  

Other symptoms may include increased risk for infection, increased bruising, acne, female facial hair, irregular menstrual periods, and even potential impairment of brain function.

"When patients have too much cortisol, one of the most noticeable physical differences we usually see is weight gain and in a very particular distribution," says Dr. Sadhu. "It usually concentrates in the face and cheeks, known as 'moon face.' We may also see a 'buffalo hump,' or fat on the back of the neck, and in the abdomen."

"A patient's driver's license is a good historical reference to identify these symptoms," she adds. "If the patient has Cushing disease, it's very likely there will be a stark difference between the old photo and the pattern of new sudden weight gain."

When should you be worried about your cortisol levels?

Cushing syndrome requires medical treatment. If you're concerned you may have a cortisol imbalance due to the associated symptoms, Dr. Sadhu says to talk to your primary care physician about the symptoms you're worried about.

"Cushing's and other cortisol-related conditions have very specific symptoms and diagnoses, such as rare cortisol-secreting tumors. But, luckily, it doesn't happen very often."

It is estimated that only 40 to 70 people per million have Cushing syndrome.

"It's important to talk to your primary care doctor and get checked out," says Dr. Sadhu. "They can examine you, talk about your history and determine whether your symptoms are from life stressors, other conditions or an actual cortisol disease process. There are specific tests to start with. Then they can refer you to an endocrinologist for further testing or evaluation."

There are a few ways healthcare providers can test your cortisol levels based on your symptoms, including:

• Urine tests
• Blood tests
• Salivary tests
  
  

"If it's not a disease like Cushing syndrome," says Dr. Sadhu. "Then you discuss other treatment options to address your symptoms, like stress management, lifestyle changes, medication or other interventions."

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