Stress is not harmful when experienced in small doses and for short durations. However, when stress becomes chronic, then this can detrimentally affect your cardiovascular health.
When you have stress, the fight or flight response, the stress response, is activated. Stress (and fear) activates the amygdala, which in turn simultaneously activates the sympathetic nervous system and the HPA axis.
The sympathetic nervous system innervates the heart and arteries directly, where activation of the sympathetic nervous system increases heart rate and contraction, and constricts blood vessels to increase blood pressure.
Chronic stress leads to chronic activation of the sympathetic nervous system, which leads to increased risk of cardiovascular disease, high blood pressure, stroke, or sudden death (Hering et al., 2015).
When stress activates the HPA axis, it involves the eventual release of the stress hormone cortisol to help with the stress response. However, with chronic stress, there is prolonged activation of the HPA axis and chronic release of cortisol, which increases the risk for coronary artery disease, type 2 diabetes, and stroke (Manenschijn et al., 2013; Christensen et al., 2004).
In summary, chronic stress can lead to detrimental effects on your cardiovascular health. Therefore, it is important to manage your stress levels to maintain good cardiovascular health.