With all the diversity and ambiguity of the philosophical and physical understanding of time, we can confidently point out its main characteristics: infinity, continuity and cyclicality. Human life from the very moment of conception to death flows along the axis of time and follows its laws.

The human body is an example of a complex spatio-temporal organization. All biological processes in it are structured by time. Cyclicity is a universal property inherent at all levels of the body’s organization: at the cell level (cycles of protein synthesis, enzyme work), at the organ level (cycles of contraction and relaxation of the heart, inhalation and exhalation), at the level of the organ system (menstrual cycle, digestive cycle) … Many different biological processes must be precisely synchronized in time to ensure their normal functionality.

The human body is under the constant influence of the macrosphere. The astrological cycles of the planets are well known, which have a strict time period and determine the daily cycle of day and night, seasonal cycles and many others, studied and not known until now. Evolution has adapted the human body to these cycles. So he acquired the properties of increasing activity during the daytime, recovering at night, changing physiological characteristics depending on the season of the year or the cycle of the moon.

Cyclic changes in the functions of the human body are called biological rhythms. The rhythm in the life of organisms, coinciding with external, geographical cycles, is called exogenous, or external. The rhythm of metabolic and physiological processes of the organism itself is called internal, endogenous.

The set of biological rhythms of the body is called rhythmostasis. Human rhythmostasis is genetically determined and controlled by our biological clock. The biological clock is a collection of nerve cells located in proximity to the intersection of the optic nerves. They are responsible for the synchronization of our inner time with the time cycles of the environment, determine the time of sleep, wakefulness, activity, food intake …

Understanding that illness, leading to disturbances in the structure and functions of the human body, also disrupts its temporary organization, is the conceptual basis of chronomedicine, a science that studies the temporal organization of the human body. Modern medicine is replete with examples of the relationship between biological rhythms and disease. So in cardiology, myocardial infarction, fatal heart rhythm disturbances, pulmonary embolism and sudden death – more often occur in the early morning hours, and pulmonary edema at night.

Chronomedicine includes several areas. Chronodiagnostics studies changes in biological rhythms as a result of an illness and uses them for diagnosis. Chronotherapy uses knowledge of biological rhythms for more effective treatment. Chronoprophylaxis – knowledge of the temporal patterns of the body to prevent possible complications.

The main characteristics of biological rhythms are period (duration of one cycle), mezor (average value of the indicator during one period), amplitude (maximum positive and negative deviation of the indicator from the mezor) and acrophase (time of these maximum deviations). The disease leads to violations of the basic characteristics of rhythms and their mismatch (desynchronosis), and recovery – to their normalization. The most well studied is the circadian (circadian) biological rhythm with a period of 24 hours.

In fact, the principles of chronotherapy have long been effectively used in the treatment of patients. So, some drugs are strictly applied in accordance with circadian rhythms (in the morning or strictly in the evening), and the prevention of some diseases is carried out in accordance with seasonal rhythms.

Despite the obvious importance of biological rhythms in medicine, their use in modern medical practice is very limited. This is due to the real difficulty of collecting and comprehensive analysis of the required mass of specific medical information. With the widespread introduction of computer technology, a real opportunity has appeared to overcome this problem and optimize individual treatment programs.