The three stages of human viability are sequential stages of existence, reflecting the level of physical and psychological well-being. A normal, healthy life is characterized by good physical and mental health, the absence of serious illnesses, bad habits, and degenerative factors. This includes active participation in life, development, and self-realization. Maintaining a healthy lifestyle, proper nutrition, regular physical activity, and social activity are key. A detrimental life occurs with bad habits (smoking, alcohol and drug abuse) and chronic illnesses. Physical and psychological health declines, and the risk of developing serious illnesses and complications increases. At this stage, lifestyle changes are possible that worsen a person's condition. Near-death survival means a critical threat to life due to severe illness, injury, or dying conditions. This requires emergency measures, intensive medical intervention, and support. In near-death survival, a person is in a state of life-threatening danger, and their viability is significantly reduced. The three stages illustrate the dynamics of human health development and the importance of prevention, prompt medical attention, and developing healthy habits to maintain a high level of vitality.

There are essentially three stages of human viability: first, normal, healthy life; second, unhealthy life (bad habits, illness); and third, survival on the brink of death. Let's briefly examine the key characteristics and mechanisms of each stage and the transitions between them.

1. Normal healthy life. 

1.1 Characteristics: 

* optimal functioning of all body systems; 

* sufficient energy level for daily activities; 

* resistance to external stress factors; 

* ability to regenerate and recover; 

* positive mental and emotional state;

* fulfillment of life plans and goals. 

1.2 Key factors for maintaining: 

* balanced nutrition; 

* regular physical activity; 

* adequate sleep and rest; 

* absence of bad habits; 

* preventive medical examinations; 

* harmonious social relationships; 

* stress management. 

1.3 Critical to maintaining health: 

* regular medical examinations; 

* timely lifestyle adjustments; 

* avoiding risk factors; 

* maintaining mental and emotional balance.

2. Unhealthy lifestyle (bad habits, illnesses). 

2.1 Characteristics: 

* gradual decline in the body's functional reserves; 

* development of chronic diseases or their precursors; 

* development of addictions (nicotine, alcohol, drugs, etc.); 

* decreased performance and quality of life; 

* increasing mental and emotional discomfort; 

* disruption of social connections and professional activity. 

2.2 Mechanisms of transition from Stage 1: 

* systematic neglect of healthy lifestyle principles; 

* accumulation of stress factors; 

* genetic predisposition to certain diseases; 

* unfavorable environmental conditions; 

* socioeconomic difficulties.

3. Survival at the brink of death.

3.1 Characteristics: 

* critical decline in functional capacity; 

* multiple systemic impairments; 

* need for ongoing medical support; 

* limited ability to care for oneself; 

* markedly reduced quality of life; 

* high probability of death without intensive care. 

3.2 Typical conditions: 

* terminal stages of chronic diseases; 

* severe injuries and their consequences; 

* multiple organ failure; 

* comatose states; 

* irreversible neurological impairment.

The transition between stages of vitality occurs gradually: 

* at stage 1, prevention significantly reduces the likelihood of health degradation and progression to stage 2, ensuring longevity [1-5]. 

* at stage 2, a return to stage 1 is possible with lifestyle adjustments and treatment; 

* at stage 3, recovery to stage 1 is often impossible, but stabilization is possible. 

This article is based on personal experience over eighty years of active life. At the age of sixty, three cancers were diagnosed: basal cell carcinoma, colon adenocarcinoma, and prostate adenocarcinoma. The basal cell carcinoma on his right shoulder and the colon adenocarcinoma were surgically removed. The prostate adenocarcinoma is being suppressed with a hormonal drug. During the third stage of survival, he gained a strong sense of vitality, which helped him progress to the second stage [6]. The author shares this experience of vitality in the article. Chapter 2 is devoted to normal, healthy living. Chapter 3 examines unhealthy living with unhealthy habits and illnesses. Survival at the brink of death is described in chapter 4.

2. Normal, healthy life in society 

Normal, healthy life in society is a harmonious combination of physical, mental, and social well-being, allowing for the full fulfillment of personal and social functions. Key components:

1. Physical well-being: 

* regular physical activity (sports, walks, exercise); 

* balanced diet; 

* adequate sleep (7-9 hours); 

* hardening; 

* cessation of bad habits; 

* personal hygiene; 

* preventive medical examinations. 

2. Mental well-being: 

* ability to manage emotions and stress; 

* adequate self-esteem; 

* ability to reflect and introspect; 

* having goals and meaning in life; 

* ability to set boundaries; 

* constructive conflict resolution skills. 

3. Social well-being: 

* good relationships with family and others; 

* having a supportive social circle; 

* ability to cooperate and work in a team; 

* respect for others and their boundaries; 

* participation in public life; 

* professional self-realization. 

4. Important principles:

* Routine and rhythm: a healthy balance of work, rest, and sleep. 

* Balance: an even distribution of time between work, family, hobbies, and self-development. 

* Responsibility: an awareness of one's personal role in maintaining one's own health. 

* Flexibility: the ability to adapt to change without losing one's inner balance. 

* Mindfulness: being mindful of one's responsibilities, needs, and boundaries of normalcy. 

5. Practical recommendations: 

* Start the day with exercise (even 5-10 minutes gives an energy boost). 

* Include more vegetables, fruits, and whole grains in your diet. 

* Make time for relaxation and hobbies—this prevents burnout. 

* Maintain social connections: meet with friends, participate in events. 

* Learn to talk about your feelings and needs—this strengthens relationships.

* Get regular medical checkups, even if nothing is bothering you. 

* Practice New Testament living and prayerful fellowship with the Lord.

Normal, healthy lifestyle reduces the burden on the healthcare system; increases productivity; strengthens social ties; creates a positive example for others; and promotes sustainable social development [7]. 

Normal, healthy life in society is not only the absence of disease but also an active pursuit of balance in all areas: physical, mental, spiritual, and social [8-10]. This is a process that requires conscious effort and yields long-term benefits in the form of improved quality of life and satisfaction.

3. A person's harmful lifestyle in society 

A person's harmful lifestyle, with bad habits and underlying health conditions, has a devastating impact on both the individual and society as a whole. Bad habits are regularly repeated actions that damage health, reduce productivity, and interfere with a fulfilling, normal life. When they develop into an addiction that is difficult to correct, this leads to negative consequences.

1. Impact on human health. 

Bad habits become the basis for the development of chronic diseases and increase the risk of premature disability. Some of them: 

1.1 Smoking affects the respiratory system: it causes chronic inflammation, increases the risk of lung, laryngeal, and bladder cancer, and chronic obstructive pulmonary disease (COPD). It affects the cardiovascular system: it provokes hypertension, heart attacks, and strokes. It worsens oral health (periodontitis, leukoplakia, melanosis), changes tooth color and bad breath. In men, it can lead to erectile dysfunction. 

1.2 Alcoholism causes liver cirrhosis, alcoholic cardiomyopathy, and gastrointestinal, renal, and pancreatic dysfunction. It affects the nervous system: memory, vision, and vestibular function deteriorate; in severe cases, psychosis, dementia, and dementia develop. Alcohol increases the risk of bronchitis, tuberculosis, and pulmonary emphysema. It can also disrupt the reproductive system in both men and women. During conception, it increases the risk of having a child with mental and physical developmental delays. 

1.3 Drug addiction harms all internal organs and can lead to arrhythmia, heart failure, muscular dystrophy, and heart attacks. It impairs gastrointestinal function and disrupts reproductive function. Injecting alcohol increases the risk of HIV and hepatitis. It often causes mental disorders. 

1.4 Poor diet and a sedentary lifestyle contribute to obesity, type 2 diabetes, cardiovascular disease, osteoporosis, and depression.

2. Social Consequences. 

Bad habits destroy social connections, reduce quality of life, and harm society. Some social consequences: 

2.1 Destruction of family relationships. Alcoholism and drug addiction often lead to divorce, and children in such families are often left without supervision and may adopt their parents' bad habits. 

2.2 Problems at work. Addiction can lead to lateness, missed deadlines, absenteeism, and showing up for work drunk. This reduces productivity and can lead to dismissal.

2.3 Increased crime. Drug addiction and alcoholism are often associated with aggressive behavior, which increases the risk of domestic conflicts, violence, and other crimes. 

2.4 Social isolation. People with bad habits often experience communication difficulties and lose social connections. 

2.5 Financial problems. Addictions can lead to debt, loss of property, and the need to take out loans. 

2.6 Passive impact on others. Smoking harms not only the smoker but also those who inhale the smoke. Alcohol can encourage risky behavior, such as car accidents and sexually transmitted infections.

3. Reasons for the development of bad habits. 

Many factors influence the development of bad habits: 

* a person's worldview; 

* social environment (fashion for bad habits in a certain group, influence of family and friends); * emotional environment (stress, traumatic experiences, psychological problems, including those developed in childhood); 

* boredom, idleness, poor time management; 

* curiosity.

4. Prevention and assistance. 

To reduce the prevalence of bad habits, comprehensive measures are important: 

* promoting a normal, healthy lifestyle; 

* developing sports and creating employment opportunities for children and adolescents; 

* psychological support (hotlines, helplines); 

* educational programs in schools involving psychologists, doctors, and former addicts. 

It's important to understand that bad habits are not only a personal matter but also a social problem that affects several generations and society as a whole. 

At the first signs of addiction, it is recommended to seek the help of specialists—psychologists, addiction specialists, and psychotherapists. Only those with a strong will and resilience can cope with severe addictions on their own.

4. Survival in a Human Society on the Brink of Death 

Human survival on the brink of death is a complex phenomenon that encompasses both physiological and psychological aspects. Research in this area draws on the experiences of people who have survived severe illnesses and other life-threatening circumstances [11].

1. Psychological Survival Mechanisms. 

In his book "The Enlightened Heart," Austrian psychologist Bruno Bettelheim, who survived imprisonment in the Dachau and Buchenwald concentration camps, described several psychological mechanisms that help preserve the personality under conditions of systematic oppression. 

1.1. Inner Independence. This allowed for the preservation of a sense of oneself as a subject, rather than an object of oppression. This idea has parallels with the philosophy of the Stoics, who argued that a person can maintain freedom even under conditions of physical slavery if they control their internal reactions and perceptions. 

1.2. Childhood Regression. Under conditions of complete helplessness and dependence, some people exhibit childlike behavior, hoping for help and protection. This serves as a survival mechanism, although it leads to personality infantilism. 

1.3. Identification with Strength. Acquiring strong psychological traits within oneself to feel stronger and more secure. 

1.4. An Inner, Purposeful Will to Live. The strongest motivation for survival can be something that makes a person willing to stay alive at any cost. For example, a strong attachment to loved ones—parents, spouse, children.

2. Psychological aspects of dying. 

Medical psychologists note the following psychological aspects of dying: 

2.1. The person refuses to accept reality. 

2.2. The person may express anger at others and the situation. 

2.3. Attempts to negotiate with higher powers or medical professionals to prolong life. 

2.4. Awareness of the inevitability of death. The person may withdraw into themselves and experience deep sadness. 

2.5. Resignation and readiness to face death. The person may experience a sense of peace and completeness.

3. Factors Affecting Survival. 

Factors that can prolong life in critical situations include: 

* meaning and purpose (unfinished business, desire to see loved ones); 

* physical resources (body fat reserves, access to water and food);

* psychological qualities (hope, self-confidence, ability to self-organize); 

* experience of surviving in extreme conditions; 

* belief in eternal life. 

Survival at the brink of death is a multifaceted process dependent on physiological, psychological, and social factors. The experience of such situations often radically changes a person's personality and their attitude toward life and death.

Health preservation technologies and measures help maintain human health. Orthodox spiritual development helps people maintain a normal life. 

Health preservation technologies are a set of methods, tools, and approaches aimed at maintaining and improving human health, preventing disease, and improving quality of life. They include the following key areas:

1. Preventive measures: 

- Vaccinations and immunoprophylaxis to prevent infectious diseases. 

- Screening examinations for early detection of diseases. 

- Healthy lifestyle education programs. 

2. Health and an active lifestyle: 

- Regular physical activity and exercise therapy. 

- Proper nutrition and diet therapy. 

- Weight control and quitting bad habits. 

3. Health monitoring technologies: 

- Use of wearable devices (fitness bracelets, smartwatches) to track health indicators (heart rate, physical activity level, sleep quality). 

- Electronic medical records and telemedicine for remote monitoring and consultations [12].

4. Medical innovations: 

- Genetic diagnostics and personalized treatment. 

- Use of modern diagnostic methods (MRI, ultrasound, laboratory tests). 

- Rehabilitation technologies and physiotherapy. 

5. Psychological support and stress management: 

- Relaxation techniques, meditation, cognitive behavioral therapy. 

- Programs for developing emotional resilience. 

6. Environmental hygiene and sanitation: 

- Personal hygiene.

- Monitoring the quality of water, air, and food. 

These technologies help not only prevent illnesses but also promptly detect and treat them, promote healthy habits, and improve overall vitality.

Orthodox normalization of life is the process of bringing a person's life into alignment with the spiritual and moral principles of Orthodoxy. It includes the following key aspects:

1. Spiritual renewal and prayer: 

— Regular participation in church services, reading prayers and spiritual literature. 

— Persistent pursuit of inner harmony, repentance, and spiritual growth. 

2. Following moral commandments: 

— Observing God's commandments, such as love for one's neighbor, honesty, humility, and mercy. 

— Refraining from sinful actions such as lying, envy, anger, and breaking the commandments. 

3. Maintaining traditional values ​​and lifestyle: 

— Observing church holidays, fasts, and rituals. 

— Cultivating respect for family values, honesty, and piety in oneself and others. 

4. Moral and physical health: 

- Caring for one's body as a temple of the spiritual. 

- Giving up bad habits, caring for one's health, and behaving honestly and decently. 

5. Social and charitable activities: 

- Assisting those in need, participating in church and charitable projects. 

- Showing love and compassion for others in everyday life. 

Orthodox normalization of life presupposes a holistic approach—a combination of spiritual practices, moral self-improvement, and health care, which promotes personal harmony and strengthens one's spiritual and physical well-being [13-14]. It supports the stage of normal, healthy human vitality [15-16].