Psychological stress is behind many, if not most, disease and can cause:
Carotid atherosclerosis, narrowing of the two major arteries that carry blood from the heart to the brain.
Inflammation, thereby leading to cardiovascular disease.
Immune suppression, increasing the risk of viral infections.
Excess histamine production, which can trigger severe asthma and allergies.
Elevated glucose levels, by triggering fight-or-flight hormones, causing chronic high blood sugar and diabetes.
Deleterious brain effects, such as producing fewer neurons than normal, creating an imbalance that could lead to mental illness.