The Science of Stress


Authored on

May 24, 2022
Jayatri Das, Ph.D.

Imagine something that’s scary. Exhausting. Maybe overwhelming. Or even incredibly exciting. Any of those might immediately spark a feeling for you about what it means to be “stressed out.” From a scientific perspective, however, stress is a complicated thing. In general, scientists think of stress as your body’s response to being pushed out of balance. But what causes stress, how your body responds to stress, and the long-term impacts of stress all involve many factors: physiological, behavioral, emotional, and cognitive. 

The origins of our stress response go back to ancient times. Imagine being one of our prehistoric ancestors facing down a saber-toothed cat. As you perceive the danger, your brain sends signals to your body to do things it might not normally be able to do, like run faster to escape the threat. The brain activates various glands, which in turn produce a surge of hormones that dramatically affect your body. Your heart beats faster. Your breathing speeds up. Your muscles tense. You feel a jolt of energy. You’re on guard, prepared to attack or run. This is what we call the “fight or flight” response. 

Modern causes of short-term stress are typically a far cry from a wild predator—more often we experience psychological and environmental stressors like a big competition or deadline, financial challenges, major life changes, or feeling unsafe in a given situation. But your body uses the same ancient toolbox to respond, activating the same systems. Just like our ancestors got that extra edge to flee from the threat of a predator, the stress response can be useful. Maybe it motivates you to push through and finish a race or boosts your performance at work. It’s also important to understand that the same stressor can cause different levels of stress in different people. Factors ranging from life experience to brain chemistry influence how we each perceive the challenge of a stressful situation. 

Most of the time, the stress response relaxes once the perceived threat (or deadline or life event) passes, and your body recovers its balance. When a threat continues over time, however, the stress response stays in a heightened state of alert. This chronic stress can take a long-term toll not only psychologically, but also physically. It can compromise your immune system, affect your heart health, and increase your risk of addiction or anxiety disorders. 

How can we reduce stress? Exercise, proper nutrition, time management, and sleep all help us cope with stressful situations in our lives. Learning and practicing mindfulness can also help. Dealing with chronic stress is more challenging, but try to focus on the things you can change and build supportive relationships. And understanding how our bodies respond to stress can help us know when to seek help. If you feel consistently overwhelmed, know that you don’t just have to push through—talk to a mental health professional to help you find your way back to balance. 

Dr. Jayatri Das, Chief Bioscientist at The Franklin Institute

About the author

Jayatri Das, Ph.D.

As Chief Bioscientist at The Franklin Institute, Jayatri Das helps us understand ourselves. How do our brains work? How do our neighborhoods affect our health? How will new technologies change our future? As an awesome science communicator, she brings us all into the conversation!