Undoubtedly, the health of people in the community is very important. Human societies cannot survive without maintaining health and hygiene. Illness and disability disrupt human relationships and thus deprive human beings of a sense of security and solidarity. Therefore, it is natural that medicine always strives to maintain and improve the health of society with the aim of gaining new information. Maintaining the physical health of individuals in a community means preventing the spread or eradication of diseases that cause disability or extinction  (Figure 1). As health as a duty of medicine and in the field of medical sciences is of great importance and maintaining the physical health of individuals depends on it, the health and mental health of individuals in society has also received special attention from experts and practitioners. What is now known as mental health in various societies is in fact a specialized field in the field of psychiatry. But what should be noted at the outset is that given the major differences between mental illness and physical illness, mental health has many difficulties in achieving its goals. Behavioral, emotional, and cognitive symptoms may occur in respond to stressful events one or more stressors can lead to psychiatric illness and disorders . The number and severity of stressors do not always predict the severity of symptoms and psychiatric disorders. The stressors may be single, multiple, or persistent. Physical illness is one of the stressors that can be considered a risk to mental health if it becomes chronic. Community and specialists in various fields of medicine, such as psychiatrists, play an important role in the mental health of patients with physical illnesses. For example, the family and the community can improve mental health or at least improve mental health by observing the case of preventing physical illnesses and providing emotional and social support to patients after suffering from physical illnesses and accepting the illness instead of rejecting them .
Mental health concepts
The World Health Organization (WHO) defines mental health as "mental health within the general concept of health, and health means the full ability to play social, mental, physical, and health roles, not just the absence of disease or retardation." In this definition, as it was observed, adaptation to the environment is very important, according to which a person who can adapt well to his environment, family, colleagues, neighbors and society in general, will be normal in terms of mental health. This person will move forward with a satisfactory mental balance and will resolve their conflicts with the outside and inside world and will resist the inevitable failures of life [5-8].
Figure 1: Chemotherapy Infusion for Breast Cancer: Procedure and Side Effects 
Inappropriate and unexpected treatment will make the patient be mentally ill. Because he will face the risk that he will show his unresolved conflicts as a neurotic person. Therefore, people's mental health is very important and for this reason, different communities have been mobilized today to organize sites related to mental health and mental illness prediction. These sites, which can have high human and economic values, require that mental health needs be recognized above all else. Mental health needs are to know the factors that guarantee it, especially in children, to understand the causes of the disorder and to learn how to treat mental illness. In 1948, the Preparatory Commission of the Third World Mental Health Congress proposed a two-part definition of mental health:
1- Mental health is a state that physically, mentally and emotionally to the extent that it is compatible with the mental health of others, facilitating the most desirable growth for the individual.
2- A good society is the one that provides such growth for its members and at the same time guarantees its own growth and shows tolerance towards other societies.
The WHO defines mental health in terms of biological and social aspects. According to this organization, mental health for a person has the ability to create balanced relationships with others and the ability to participate in changes in social and material environment or the ability to help change in a constructive way. Mental health also requires coordination between instinctual desires. This harmony contributes to the unity of the individual, not to some instinctual tendencies to oppose and suppress other tendencies. In recent years, the Canadian Mental Health Association has defined it in three parts:
Part One: Attitudes towards Self,
Part Two: Attitudes toward Others (Comfort with Others), and
Part Three: Attitudes toward Life (Meeting Requirements) life). According to this association, there are signs that inform us of psychological difficulties, especially in self-absorption, aggression, abstinence, insomnia, anxiety, daydreaming, hypochondria, mood swings.
In addition to having good mental health, there are conditions including: Facing reality, adapting to change, having room for anxiety, low expectations, respecting others, and helping people (Figure 2) .
Prevention in mental health
In mental health in general, the goal is to reduce illness and its complications. To achieve this goal, three issues must be pursued: prevention of disease, i.e. primary prevention, treatment of the disease before it leaves lasting effects, namely secondary prevention, and reduction of disabilities resulting from the disease or rehabilitation of patients, i.e. tertiary .
1- Primary prevention: In the 1960s and 1950s, the world hoped to prevent basic mental illness. It was believed that if children were properly raised and the principles of psycho-social development were applied to them, and a strong self were developed in them, they could be prevented from developing any mental illness. For this reason, a mental health program to educate any individual or group that has an impact on a child's development, including obstetricians, pediatricians, and education officials, i.e. school and family, was challenged, and it was later emphasized that children at risk that their parents with special educational and environmental conditions are not able to develop enough in them. Such group needs more attention and mental health planning. For this reason, centers were set up for adoption, assistance, and charitable activities for special educators. In the following decades, the above movements to prevent mental illness failed. Because the theories of etiology of mental illness, considered more as psycho-social, were not appropriate. After that, the more the genetic and biological meaning of mental illness was discovered, the more the reason for the failure of disease prevention methods became understandable, then new methods of disease prevention were introduced . Genetic counseling was considered for those diseases in which the family plan was proposed. On the other hand, the involvement of psychological stressors in igniting psychological differences caused the necessary training to help people to reduce the effects of these stressors in life for the initial prevention of diseases. Many medical conditions, including infectious and cardiovascular diseases and vitamin deficiencies that have neuropsychological consequences, can also be prevented, as well as the use of calcium and substances such as cocaine and drugs during pregnancy that have psychological effects on the baby. These and similar issues constitute the scope of primary prevention in mental health.
2- Secondary prevention: Early recognition and immediate treatment of neuropsychiatric disorders that lead to the prevention of permanent destruction of diseases is the field of secondary prevention. In the United States, the National Institute of Mental Health (NIMH) and the Child and Adolescent Program (CACSP) are responsible for this prevention. In this system, all facilities are used for the rapid and timely diagnosis and treatment of behavioral diseases in children and adolescents and assistance to their families. Psychiatrists and other mental health professionals are part of the treatment team. Crisis intervention mechanisms and training in how to treat patients in the family are among the mental health tasks associated with secondary prevention .
3- Tertiary prevention: Reducing the functional destruction of the individual in the community due to mental illness is called tertiary prevention. According to this definition, treatment methods in resistant mental illnesses are proposed in this prevention. In other words, reducing the residual effects of the disease on the individual in tertiary prevention is emphasized. The primary goal in this type of prevention is actually rehabilitation of the mentally ill. Because most severe mental illnesses have recurrent recurrences. Patients' rehabilitation cannot be delayed until complete cure of the disease.
On the other hand, in psychiatry, secondary and tertiary prevention should be done together and with the current knowledge, it is sometimes difficult to correctly determine the symptoms such as anorexia, indifference (astonishment), how many symptoms of the disease and how much of the remaining symptoms of the disease. Tertiary prevention and rehabilitation in psychiatry is often discussed with patients suffering from severe and debilitating mental illness. Schizophrenia and most severe mood disorders and some debilitating personality disorders are among these diseases. All of these conditions, especially schizophrenia occur in late adolescence and early adolescence. Naturally, the academic and career advancement that occurs most at this age greatly affects the individual. After the period of illness, most patients suffer from occupational, social and interpersonal disabilities. For this reason, its rehabilitation will be a complex process that will meet the psychological, social and medical needs. Psychiatry is now trying to reduce the length of hospital stay, even in acute cases, so that the patient can be more present in the community and rehabilitate as soon as possible . Recently, terms such as general prevention, aimed at the attention of society and everyone, and selective prevention aimed at people who are most at risk of mental illness, and case prevention aimed at people at high risk of mental illness with strong biological symptoms have been introduced, but this division has not been addressed in the new American Psychiatric Classification.
Cancer is a disease in which the cells of the body grow uncontrollably due to damage to their natural regulatory mechanisms. In most cancers, solid glands in certain parts of the body are commonly found in the skin, breast, lungs, intestines, or prostate glands are formed. The disease may spread through the blood and lymphatic system. As our understanding of cancer has increased over the past 20 years, lifestyle changes, effective screening programs, and new types of treatment have led to advances in the prevention and treatment of cancer. The term cancer is derived from the Greek word crab. The ancient Greek physician Hippocrates likened a diffuse cancer to a crab. However, our understanding of the disease has improved since then. But this explanation still seems appropriate. An important feature of a cancerous gland is its ability to spread throughout the body .
Genetic basis of Cancer
The discovery, which shows genetic damage, could lead to cancer. One of the most important advances in cancer research was in the late 1970s. Each cell contains genetic information in the form of more than 90,000 pairs of genes that control its activities. A cell becomes cancerous when certain genes responsible for controlling its vital processes, such as cell division, are damaged. These defective genes may have been inherited, or caused by carcinogens such as sunlight, tobacco smoke, etc. Cells are constantly exposed to carcinogens, but for a variety of reasons they rarely become cancerous. One is that cells can usually repair their damaged genes, and the other is that more than one gene must be damaged to cause cancer, and the other is that the immune system often abnormally produces cells before they can reproduce enough, and they destroy the cancerous gland  (Figure 3).