How Stress Affects Your Body
To give you a quick overview, when you experience acute stress — be it real or imagined, as your body cannot decipher the difference — your body releases stress hormones (such as cortisol) that prepare your body to either fight or flee the stressful event.
Your heart rate increases, your lungs take in more oxygen, your blood flow increases, and parts of your immune system become temporarily suppressed, which reduces your inflammatory response to pathogens and other foreign invaders.
When stress becomes chronic, your immune system becomes increasingly desensitized to cortisol, and since inflammation is partly regulated by this hormone, this decreased sensitivity heightens the inflammatory response and allows inflammation to get out of control.
Inflammation, in turn, is a hallmark of most diseases, from diabetes to heart disease, and cancer. Elevated cortisol levels also affect your memory by causing a gradual loss of synapses in your pre-frontal cortex.
Stress may even trigger the onset of dementia. In one study, 72% — nearly three out of four — Alzheimer's patients had experienced severe emotional stress during the two years preceding their diagnosis.