How Chronic Stress Disrupts Your Body's Natural Cortisol Balance

Online, cortisol often gets blamed for everything from a puffy face to weight gain around the midsection. And while it can play a role in symptoms that can arise from chronic stress, it’s not in the oversimplified way social media often suggests.

We spoke with Dr. Nadir Mulla, a primary care physician with Houston Methodist, about the cortisol curve and how it supports the body’s natural daily rhythm. When that rhythm is working well, cortisol rises in the morning and falls at night. But chronic stress, poor sleep and other everyday habits can keep that curve from following the pattern the body prefers.

And while cortisol levels get blamed online, Dr. Mulla says true cortisol disorders are rare. More often, the bigger issue is not a broken hormone system, but a lifestyle pattern that keeps the body from settling into its natural rhythm.

What cortisol does in the body

“Cortisol is commonly known as the stress hormone,” says Dr. Mulla. “I think that’s a little bit of a misnomer. I would say it’s more of an energy mobilization hormone.”

The body needs cortisol to function. Produced by the adrenal glands, the hormone is released when the body needs energy to respond to what is happening physically or psychologically. It plays a role in many of the body’s functions, including:

• Blood pressure

• Blood sugar levels

• Circadian rhythm (sleep-wake cycle)

• Heart rate

• Immunity (fighting infections and inflammation)

• Metabolism

Dr. Mulla notes that cortisol is not the same thing as the first rush you feel when something startles you. He explains that adrenaline and norepinephrine drive that immediate fight-or-flight response. Cortisol tends to rise later and then contributes its own effects after that first wave passes.

What is a healthy cortisol curve?

A healthy cortisol pattern is not about keeping the hormone low all the time. It’s about timing.

“The general trend that you need to understand is that cortisol is going to be highest in the morning and lowest, almost undetectable, when you’re about to go to sleep,” says Dr. Mulla.

That daily rhythm is heavily influenced by light entering the eyes and the brain’s internal clock, the suprachiasmatic nucleus (SCN). The SCN drives the 24-hour rhythm of cortisol release by sending signals that tell the adrenal glands how much cortisol to release in the body.

When the SCN detects light from the eyes, it begins to mobilize the body to wake up.

“When we wake up in the morning, we do so naturally through the cortisol awakening response,” Dr. Mulla says. “In the morning, your brain sends signals to raise cortisol, and what actually wakes you up is that increased blood sugar and energy that results from the cortisol rising, which ideally spikes at the beginning of the day.”

During the process, cortisol helps mobilize energy by telling fat tissue to release stored energy, prompting the liver to make sugars and break down some protein in muscle. In the right context, that can leave you feeling more alert and ready to get moving.

As the day progresses, your body will lower cortisol levels until they are almost undetectable. Lower cortisol levels help support the body’s ability to settle into sleep. When that natural cortisol decline doesn’t happen as it should (thanks to a variety of issues — more on this below), the result can be a frustrating mix of feeling tired and still feeling too activated to fully rest.

How chronic stress can throw off cortisol balance

Chronic stress can show up in the body with issues like fatigue, poor sleep, nonstop mental load and much more. Plus, how we respond to stress— using caffeine to stay alert, not enough recovery or a go-go-go routine — Dr. Mulla says can affect the cortisol curve.

“A lot of times our cortisol curve will fluctuate more with chronic stress, poor sleep habits, overtraining and not enough recovery,” says Dr. Mulla. “Oftentimes, you’ll find that the cortisol curve, rather than being high in the morning and low in the evening, will tend to be a medium spike in the morning and still not completely low in the evening.”

An irregular curve can explain why some people can still feel wired at night and exhausted in the morning. If cortisol remains higher than it should in the evening, the body may not get the full nighttime decline it needs to fully rest. Cortisol levels are usually lowest in the middle of the night, around 3 a.m. If you’re waking up well before your alarm and have trouble getting back to sleep, cortisol may be spiking too early. With the timing off, you may not feel as alert at 8 a.m., when cortisol levels are usually the highest in a healthy curve.

Dr. Mulla says that if your brain keeps getting the message that you’re under pressure or want to be awake, it can continue signaling the body to stay activated.

“When you're sick, your body needs to mobilize energy so cortisol will rise. When you exercise, cortisol will rise. When you're psychologically stressed, cortisol will rise. So, if it's chronically activated, if you're not sleeping well, if you're not getting proper nutrition, if you use too much caffeine, nicotine or alcohol, all this can affect your cortisol levels,” Dr. Mulla says. “Now, is that saying that your cortisol is the issue or is it your lifestyle being an issue? True cortisol issues are actually very rare, so it's much more likely a lifestyle or behavioral change that can help fix a curve to one that peaks in the morning and decreases in the evening.”

Why your morning and evening routines matter to reset the cortisol curve

Since cortisol is tied so closely to the body’s internal clock, the habits that anchor your mornings and evenings can make a real difference. Dr. Mulla says diet, staying hydrated and sleep hygiene are all incredibly important, as well as paying attention to when you do certain activities, such as light exposure and exercise.

Get light in the morning, but limit at night

“Within the first hour of waking up, you have a special opportunity that if light enters your eyes, ideally sunlight, that can stimulate receptors in your retina to actually raise your cortisol a little bit more,” Dr. Mulla says. “And that's ideal for getting that nice cortisol peak in the morning.”

And if you’re watching TV or doomscrolling right up to the moment you say lights out (or you’re doing these activities in bed), Dr. Mulla says your body is taking in more light than you may realize.

“Let's say you're still sending heavy light signals into your eye in the evening, especially with blue light, or short wavelength light,” Dr. Mulla says. “That is going to activate your body to respond in kind, causing you to have increased cortisol during the nighttime.”

Strategically time (and potentially limit) your caffeine intake

Dr. Mulla says that timing caffeine intake can help you ward off an unwanted slump and avoid feeling wired when it’s time to wind down.

“A lot of people experience a midafternoon crash, which can be attributed to cortisol coming down a little too quickly, amongst other issues,” Dr. Mulla says. “Some people take their caffeine first thing in morning but delaying caffeine intake by 30 or 60 minutes after waking up can help prevent at least one component of that midafternoon crash.”

He says avoiding caffeine and alcohol too close to bedtime can help, too. As for giving up caffeine altogether, Dr. Mulla says it’s not necessary, especially if you’re someone who has a morning cup of joe on the regular.

“There are studies on this. Your body's really good at recognizing stress, especially new stress. So, if there are two people, one person who drinks caffeine every day and another who never drinks caffeine, the person who doesn’t drink caffeine regularly sees the larger cortisol spike,” Dr. Mulla says. “If you drink caffeine four or five times a week, your cortisol response is going to be much more blunted compared to someone who doesn't.”

RELATED: QUIZ: Are These Afternoon & Evening Habits Ruining Your Sleep?

Practice good sleep hygiene

Creating a nightly routine and being consistent with it can help you work on your cortisol curve. This can include turning lights down, limiting screen time a few hours before bed and a general focus on winding down and relaxing. This means avoiding things that get you into an activated state — high intensity exercise, eating a heavy meal or caffeine. Make it so your bedroom is ready for rest: cool, dark, quiet and distraction-free.

“Having an evening routine where you wind down and calm down is actually really beneficial,” Dr. Mulla says. “The SCN will adapt to some of these habits, and over time, you can start to feel more relaxed and even sleepy when you are ready to end the day.”

Another thing that helps, and is a big tenet of good sleep habits, is keeping a consistent wake time (even on weekends or on your days off).

“The best thing that you can do for cortisol regulation is going to be waking up at the same time every day,” Dr. Mulla says.

If falling asleep is hard because your mind will not slow down, Dr. Mulla says breathing techniques can help activate the body’s rest-and-relax response. Deep breathing can stimulate the vagal nerve and help bring down an elevated state, which is one reason calming breathing exercises can feel useful before bed.

Why most cortisol claims are oversimplified

A lot of the online cortisol conversation focuses on extremes. Dr. Mulla says true cortisol disorders do exist, but they are rare. He notes that truly high cortisol occurs in only about two to three cases per million people, while truly low cortisol affects about 100 to 150 people per million.

When cortisol is pathologically high or low, the symptoms are more specific. Dr. Mulla associates high cortisol with signs such as easy bruising, purple stretch marks, muscle weakness, getting thinner in the arms and legs and carrying more weight in the midsection or face. For low cortisol, he points to fatigue, weakness, low blood pressure and skin darkening.

That is different from the more ordinary body changes people often worry about. Dr. Mulla says people naturally lose muscle over time and may hold onto fat more easily as they get older. He also says where someone stores fat can vary by person and by genetics, which is one reason a rounder face or changes in the midsection are not automatically signs of a cortisol disorder.

“I think it's very reasonable to have the fear, especially given the content that’s online, and I just want people to know that their symptoms are very real,” Dr. Mulla says. “Fatigue is very real, being unable to sleep yet tired at night is very real. Feeling like you don't have enough energy to do the day is very real. And I think that a lot of times there's other explanations that can better explain what's going on in terms of why you're feeling that way, and very rarely is it that something is particularly wrong with your body's cortisol. I think cortisol is the messenger, it's a symptom of other problems, whether it’s sleep apnea and other sleep disorders, stress or anxiety, depression, insomnia, shift work, jetlag.”

Why ‘cortisol cocktails’ and supplements are not the answer

So-called cortisol cocktails, or adrenal cocktails, make the rounds online as a popular evening mocktail. They can include coconut water, orange or grapefruit juice, salt, and some individuals include magnesium. Dr. Mulla says these drinks may have more of a placebo effect and that they do not replace working on the bigger habits that shape cortisol day after day.

“Grapefruit juice affects some of the enzymes that break down cortisol and some people will say that that will decrease your cortisol, sometimes by 10% or 11%. And I think that when people get focused on these specific measures, they sometimes miss the forest for the trees,” Dr. Mulla says. “This cortisol system has been designed and gone through its model for many, many, many generations before us and it's pretty fine-tuned. And I think the big thing is addressing the big habits: sleep, stress, diet and hydration. I think if you can focus on those you're going to get much more benefit.”

However, if making a cortisol cocktail helps you wind down as part of a nightly ritual, Dr. Mulla says that’s OK. But he stresses that it’s not because a specific drink is magically lowering cortisol, but because the routine itself helps reduce stimulation and cue the body to settle down.

Is cortisol testing worth it?

Cortisol is released in pulses, and Dr. Mulla says that one sample taken at one moment does not always give useful information without a lot of context. Because of that, he says cortisol testing is rarely needed for the average person unless there are more serious signs such as unexplained weight loss or weight gain, purple striae, muscle weakness or abnormal blood pressure.

If you are looking for a more practical trend marker, Dr. Mulla points to heart rate variability. He explains that heart rate variability reflects the balance between the body’s fight-or-flight and rest-and-relax systems, and that it is more helpful to watch patterns over time than to fixate on one reading. He is also clear that heart rate variability is not a one-to-one measure of cortisol.

Dr. Mulla says the most important comparison is not with someone else, but with your own baseline. What is normal for you may be very different from what is normal for another person.

When to see a doctor about fatigue, poor sleep or suspected cortisol problems

If you are concerned, Dr. Mulla suggests keeping a symptom journal of what you are feeling, when you are feeling it, and what else may be going on around those symptoms. Then, take that information to your primary care doctor. Together you can help uncover the more common issues that may be interfering with your sleep, energy and recovery.

“It’s not a sign that your cortisol system and your body system is messed up or that we need to give you medications to fix it,” says Dr. Mulla. “It’s a sign that other areas in your life could be optimized so that your body can restore its natural rhythm.”