Studies have shown that "people with higher levels of cortisol have poorer memory [...] than those in the same age bracket with less cortisol," psychotherapist Ann Russo, LMSW, tells Bustle. So if you have ongoing stress, brain fog and other memory issues may not be far behind.

Studies have also shown how you view and handle stress can change the impact it has on your brain, Russo says. "It’s important to try and reassess the situation in a more positive light," she says. Instead, try to redirect those thoughts, be present and mindful, and work on ways to alleviate your stress, Russo says, by exercising, meditating, or even seeing a therapist to learn more positive coping skills.

If you're under huge amounts of stress on a regular basis, it can eventually change the size of your amygdala — the part of the brain that plays a key role in processing emotions. And that may impact how you feel.

"Chronic stress can increase the size of the amygdala, which can make the brain more receptive to stress, creating a brain that becomes predisposed to be in a constant state of 'fight or flight,'" Maenpaa says. "You’re primed to look for threats, so you see threats wherever you go, which reinforces your brain’s belief that it is constantly under attack."

"When being upset, stressed out, and worried is chronic and extreme, people often become exhausted and are prone to giving up," Dr. Paul Napper, PsyD, co-author of The Power of Agency, tells Bustle. And this can lead to a feeling of burnout.

"Neurobiologists use the term 'allostatic overload' to describe this condition," Dr. Napper says. When you're under pressure all the time, your body can't make adjustments to help, as it typically would. You may even start to feel more stressed as adaptive challenges go unmet, Dr. Napper says, leading to a downward spiral.

Dr. Napper tells Bustle that having high concentrations of cortisol in the blood stream for a long time can damage the brain and the rest of the body, making you more vulnerable to other illnesses. Scientists are still learning about chronic stress and all the ways it can impact health, but we do know that it can increase the risk of things like cardiovascular disease, as well as anxiety and depression.

"The best course of action is to try to address living in these high-stress times proactively through increasing your level of personal agency," Dr. Napper says. "This builds confidence and is a powerful inoculant to unexpected life stressors."

"High levels of cortisol that can build up with chronic stress can wear down the brain’s ability to function normally," Diane Amstutz PhD, a psychologist at Shirley Ryan AbilityLab, tells Bustle. And that can change your brain in a pretty shocking way.

As Amstutz says, "It can literally kill brain cells and even reduce the size of the brain [...] and can also shrink the pre-frontal cortex, the part of the brain involved in self-control and emotional regulation.”

Stress can even impact your brain in a way that may make you feel less social. And again, it's all due to that excess cortisol. As Dr. Michael Genovese M.D., a clinical psychiatrist and chief medical officer of Acadia Healthcare, tells Bustle, "It can disrupt the function of a synapse (the site where brain cells communicate with each other)." A 2014 study published in Nature Communications found that chronic stress can "tear apart" synapses in the brain, which led to subjects being less social and more isolated. If you're feeling more introverted lately, stress could be a cause.

"Stress, especially chronic daily stress such as a stressful job or a chronic illness, can lead to structural changes in the brain that allow for its survival and protection," Dr. Margherita Mascolo, M.D., CEDS, chief medical officer at eating disorder clinic Alsana, tells Bustle.

Researchers have seen this in animal models, which have shown that stress "causes a reduction in neurons (nerve cells that transmit information)," Dr. Mascolo says. These changes, she says, can lead to decreases in your ability to make decisions, retrieve memories, or regulate your emotions.