Common mechanisms of the development of the body’s stress response under the conditions of war and the COVID-19 pandemic relate to its acute and chronic course, post-traumatic stress disorder, the role of the hypothalamus-pituitaryadrenal gland, the sympathetic nervous system, and the renin-angiotensin-aldosterone system, and deficiency of α-1- antitrypsin. The development of stress-induced hypertensive changes is characterized by the activity of enzymes independent of the angiotensin-converting enzyme pathway of the renin-angiotensin system, expression of miRNA, damage to the endothelial cells of blood vessels, changes in the content of neutrophils and lymphocytes, and the soluble receptor for glycosylation end products. The considered stress-induced hypertensive changes under the conditions of the COVID-19 pandemic relate to chronic hyperinflammation, emotional response, effects of catecholamines, chymase activity, redox imbalance, DNA damage, endoplasmic reticulum stress. The interaction between ACE/ACE2 and miRNA may increase the probability of SARS-CoV-2 infection in patients with hypertension. A factor in the severity of COVID-19 is considered to be clinical depression and low immunity, and the possibility of a negative effect of antidepressants is highlighted. A more aggressive course of COVID-19 in hypertensive patients is associated with low levels of nitric oxide (NO). Stress-induced hypertensive changes under the conditions of war are associated with adaptation disorders, increased randomness of heart rate changes, post-traumatic stress disorder, the development of hypertension partly of psychological origin against the background of changes in the central nervous system, immunity, and the polymorphism of the ACEI/D gene as an indicator of endurance.