Where Does Stress Come From and What Causes It?

Stress is something every human experiences, yet many people don’t fully understand where it comes from or why it shows up the way it does. Stress isn’t just “feeling overwhelmed” or “having too much on your plate.” It’s a biological response rooted in the brain and body, one designed to protect you, not harm you.

When your brain detects a challenge, threat, or even a potential threat, your stress response switches on. The amygdala (your internal alarm system) sends signals to the hypothalamus, which then activates the release of stress hormones like cortisol and adrenaline (Sapolsky, 2004). This creates a surge of energy, sharper focus, and physical alertness everything your body believes you need to stay safe.

Although this system evolved to help us survive life-or-death situations, modern stressors look very different. Instead of wild animals or physical danger, the things activating the stress response today are more likely to be emails, deadlines, parenting demands, financial pressure, chronic health issues, relationship tension, or the weight of ongoing uncertainty. The body responds as if you are in danger, even when the threat is psychological or emotional.

Our personal histories also play a major role in how stress shows up. Past experiences, trauma, and high-pressure environments can shape how sensitive or reactive our nervous system becomes over time. Research shows that people who have lived through unpredictable or overwhelming experiences may develop a heightened stress response, not because they are weaker, but because their brain has learned to stay alert for safety (McEwen, 2007). In this way, stress is not just about what is happening now, it is also about what your nervous system remembers.

External pressures are another source of ongoing stress. Workload, financial strain, environmental noise, relational conflict, caregiving responsibilities, and societal expectations can all create a sustained sense of pressure. Many people, especially women, carry a significant emotional and mental load often unseen and unacknowledged which contributes to a constant feeling of being “on.”

But stress doesn’t only come from the outside world. Internal stressors can be equally powerful. Self-criticism, perfectionism, rumination, fear of failure, and the belief that you must constantly achieve or hold everything together can activate the same stress pathways as external events. Sometimes the stress comes more from the stories we tell ourselves than from the situation itself.

Life transitions and hormonal changes also influence how reactive the nervous system becomes. Puberty, pregnancy, postpartum shifts, perimenopause, and menopause can all affect stress sensitivity and emotional regulation (Nillni et al., 2015). Major life changes even positive ones can increase stress simply because the nervous system is adjusting to something new.

Stress becomes problematic when the demands of life outweigh the resources you have to meet them. This is when chronic stress appears the sense of being stretched thin, living in survival mode, or feeling constantly on edge. Over time, this can drain energy, disrupt sleep, reduce concentration, affect immunity, and impact emotional wellbeing.

At MindfulWell, we see stress not as a personal flaw but as a signal a message from your body that something needs attention, care, or adjustment. Stress is your nervous system’s way of saying, “I need support.” And with understanding, regulation tools, boundaries, and compassionate self-care, the stress response can be softened and balanced.

If you or your whānau need support navigating stress, our counsellors and health coaches are here to help. You don’t have to manage it alone.

McEwen, B. S. (2007). Physiology and neurobiology of stress and adaptation: Central role of the brain. Physiological Reviews, 87(3), 873–904.

Nillni, Y. I., Rohan, K. J., & Zvolensky, M. J. (2015). The role of menstrual cycle phase and anxiety sensitivity in catastrophic cognitions about bodily sensations. Journal of Behaviour Therapy and Experimental Psychiatry, 46, 39–45.

Sapolsky, R. M. (2004). Why Zebras Don’t Get Ulcers. Henry Holt & Company.

World Health Organization. (2021). Stress.