Burnout has been extensively studied by many researchers over the years. However, the first report was recorded in 1974 by the German psychiatrist-psychotherapist Freudenberger and was about burnout among mental health workers [1]. The exhausted worker is paralleled as a candle whose flame flickers just before going out. Thus, this condition was characterized as "inability to perform or burnout due to excessive demands on the individual's energy, strength, or capabilities."

In 2019, the World Health Organization (WHO) recognized Burnout as a professional phenomenon. The Covid-19 pandemic and the lockdowns had a drastic influence on people's professional and personal lives, but also on the working environment in general. For this reason, more and more studies are being conducted in order to ascertain the opinions of citizen-professionals, regarding burnout, the factors that contribute to it and the effects on the organization, always taking into account the pandemic.

The problem of Burnout consists of a wide range of effects on the health professional [2,3]. Thus, as a result we have the loss of professional interest and job satisfaction, a decrease in professional performance and efficiency, culminating in mental and physical exhaustion. As a result, the employee forms a negative image of himself and his self-esteem is affected. Of course, physical symptoms also make their presence felt, such as overfatigue, general exhaustion, frequent headaches and migraines, insomnia, various musculoskeletal problems, gastrointestinal disorders and so much more [4].

This particular syndrome has high rates of occurrence with frequent reference in the field of health professionals, such as nurses. More specifically, we would say that nurses are more prone to chronic work stress due to the high level of interpersonal relationships and emotions that develop with colleagues and patients. It could be said that due to the fact that they are closer and in constant contact with the patient and his relatives, resulting in their emotional involvement and in many cases the blurring of the dividing line between personal and professional contact [5,6].

One of the main, most intense and early symptoms of Burnout is sleep disturbances. These may be due to psychological (stress) and organic factors. For example, the increased adrenaline, due to the nature and situations created during a schedule, the many and alternating shifts and working hours ascertained contribute to the change and disruption of the circadian rhythm. Nurses spend their days off work mainly trying to make up for lost sleep and rebuilding their strength [7-10].

A quality sleep contributes to concentration, easier learning, good memory, as well as good metabolism and a fairly good immune and cardiovascular system, giving a more general well-being. On the contrary, poor sleep quality is responsible for the lack of concentration, thus greater susceptibility to causing accidents and serious consequences for the quality of the services provided to the patient, with the possibility of serious nursing errors with all the ramifications at the legal and moral level, the triggering of psychiatric diseases, mental and physical fatigue, etc. [11-13]. Poor sleep quality, which is due to Burnout, has an impact on the emotional and mental health of the professional nurse, thus inevitably also on his performance in the face of any professional demands and not only that.

At this point it should be mentioned that female nurses are at greater risk of heart disease, metabolic problems, hypertension and disorders related to diabetes [14]. There is new research from Columbia University, which was published on November 24, 2021, and which deals with the impact of sleep deprivation on healthcare professionals during the Covid-19 pandemic and the disruption it causes to their mental health [15]. As a result of this research, healthcare professionals who reported poor quality sleep were twice as likely to experience symptoms of depression, 50% more likely to experience psychological distress and 70% more likely to experience anxiety, compared to those who had better quality rest [15].

This array of problems presented to health professionals is capable of exacerbating the already existing problems in the health sector. In particular, the departure - resignation of a large percentage of professionals due to increased psychological pressure which they felt from the very first period of the onset of the pandemic, leads the respective health system to even greater pressure. By extension, this results in employees who remain in their positions working more shift-hours, with greater stress, thus less quality hours of sleep and rest [15].

Undoubtedly, the good functioning of the human body is based on good rest, a good and quality sleep, which helps to balance the mind and body properly. This sequence is disrupted when the employee is in Burnout. Sleep disorders, which are intertwined with the existence of Burnout, are among the most common among health professionals and especially among those who work in a cyclical schedule and it affects everyone, regardless of age. Of course, it should be noted that the more years of work someone has, the more often sleep disorders appear during the 24 hours, such as sleepiness, which is one of the most common disorders [16].

Fatigue due to lack of sleep, especially the absence of a night's rest, leads the professional to frustration and makes him less efficient. According to studies that have been done, the primary concern for a person's health should be proper and quality sleep and adequate rest [16].

Burnout symptoms are often underestimated by professionals. They try to solve any problems they find, alone, without medical or psychological help from an expert. The wrong attempt at "self-healing" most often results in the worsening of symptoms and their progression into chronic serious problems with multi-level consequences both on the health of the health professional and on the services, he provides  [8,17].