Named the time of day when strokes and heart attacks occur most often

Most heart attacks and strokes occur precisely in the morning — between 06:00 and 11:00.

This was revealed in an interview with gazeta.ru by geneticist Konstantin Krutovsky, professor at the University of Göttingen and Siberian Federal University, and leading researcher at the Institute of General Genetics of the Russian Academy of Sciences.

"This is related to the morning physiological restructuring of the body that occurs during the transition from sleep to wakefulness. Before awakening, the level of the stress hormone cortisol spikes sharply, raising blood pressure, accelerating the heartbeat, and mobilizing energy reserves. This phenomenon is known as the cortisol awakening response. For a healthy person, this process is completely normal; however, in people with cardiovascular diseases, such a strain can become a trigger for a heart attack or stroke," the doctor explained.

In addition, most people experience a rise in blood pressure in the morning, caused by the activation of the sympathetic nervous system and vascular tone.

"During these hours, the heart works significantly harder than at nighttime. Moreover, in the morning the blood becomes more prone to clot formation — fibrinogen levels rise, platelet activity increases, and the body's ability to dissolve clots decreases. As a result, the likelihood of blockage of the heart or brain vessels increases noticeably. The situation is further aggravated by the fact that during the night the blood vessels relax, and in the morning they undergo sharp constriction under the influence of hormones and the nervous system. And if a vessel is already partially blocked by an atherosclerotic plaque, the morning constriction can critically reduce blood flow, provoke plaque rupture, and lead to clot formation," the scientist noted.

This is precisely why doctors recommend taking certain blood pressure medications in the evening — to prevent the morning pressure spike. People in the risk group are also advised not to jump into physical activity immediately after waking up and to give the body 30 to 60 minutes to adapt.

"However, a number of studies show that in 'night owl' individuals, the morning peak of cardiovascular events may shift to a later time, since their circadian rhythms are displaced. This is also important to take into account," Krutovsky concluded.