(1) The concept of health and disease. This plays an important role in defining the scope of medical treatment and the obligations of medical personnel. If the concept of health is broader, the scope of medical treatment will be broader, and the responsibilities of medical staff will be more. The World Health Organization defines health as complete physical, mental and social well-being. Many people think that this definition is too broad, which will make the scope of medical care too large and unbearable for society. The narrow definition of health only includes physical and mental health, or is limited to physical health. Another definition of health is that there is no disease, so the scope of medical treatment is limited to eliminating and controlling diseases. There is a dispute between naturalistic definition and normative definition about diseases. The definition of naturalism emphasizes that diseases deviate from natural functions in the organizational structure of species and have nothing to do with value. The normative definition emphasizes that disease is a deviation from social norms and is related to value. Such as masturbation and homosexuality, are all related to social norms and values.

② Doctor-patient relationship. The relationship between doctors and patients involves many basic problems of medical ethics, among which the most important ones are the rights of patients and the obligations of doctors. People put forward various ethical models of doctor-patient relationship. Traditional medical ethics emphasizes that everything medical personnel do must be beneficial to patients, regardless of patients' wishes. This is a paternalistic model. Later, in the West, with the development of the civil rights movement, more emphasis was placed on respecting patients' opinions, which was a model of autonomy. Someone tried to unify the two. In addition, imitating the contract mode proposed by the commodity exchange relationship, both doctors and patients are regarded as equal partners in commodity exchange, and their interests are protected by law. However, the trust nature of the doctor-patient relationship transcends the commodity exchange relationship and cannot be accommodated by the contract model. There is a de facto inequality in the possession of medical knowledge between doctors and patients. There are three criteria for moral evaluation of medical staff's behavior: whether it violates laws and administrative regulations; Whether it conforms to recognized ethical principles and moral rules; Whether he is a man of noble character. Patients have the right to basic medical services, self-determination, informed consent and privacy.

③ Reproductive technology. Reproductive technologies such as artificial insemination, in vitro fertilization and surrogate mother provide unnatural reproductive methods for human beings, which have caused a series of conceptual, ethical and legal problems. Reproductive technology makes people separate love and sexual intercourse from reproduction and procreation. Will this weaken the sacred bond of family? Will introducing a fertilized egg with a third party into marriage through artificial insemination destroy the foundation of family? What is the legal status of the children born of donor sperm artificial insemination? Should sperm donation be inspected, restricted, confidential and commercialized? What is the ethical and legal status of embryos in in vitro fertilization? Should research on human embryos be controlled? Should surrogate mothers be prohibited by law? In artificial reproduction technology, a child may have both parents who provide genetic material and development environment and parents who raise him. So what are his parents' ethical and legal obligations and rights? Should prenatal sex selection be banned? The discussion of these issues often needs to make corresponding decisions in policy and law.

④ Birth control. Contraception, induced abortion and sterilization are also technologies that separate love, sexual intercourse and reproduction, so they are opposed by religious or non-religious authorities. On the other hand, it is also a controversial issue whether people with severe mental retardation and severe mental patients should be forcibly sterilized. If we think that birth control technology can be defended ethically, then there is another question of how to defend it: Is it because the parties have the right to make their own decisions on reproductive issues, or is it because marriage and childbirth are private issues and others and society have no right to interfere? The discussion of induced abortion raises another question: Is the fetus a person? When did people start? People start from the time of fertilization, from fetal movement, from the appearance of brain waves, and from being able to survive in vitro? As long as you have 23 pairs of chromosomes, you are human, or do you have to be self-conscious and have a certain social relationship with others? Some countries stipulate that abortion is not allowed after the fetus enters the fertile period, but if abortion is needed for some reason, is it allowed? On the issue of late abortion, how to deal with the conflict of values or interests of fetus, mother, family, society and medical staff is an embarrassing problem for medical staff so far.

⑤ Genetics and eugenics. Prenatal diagnosis, genetic examination, genetic screening, genetic counseling, gene therapy, genetic engineering and other technologies are conducive to people's early detection of genetic diseases, but these technologies have caused ethical problems such as whether such examination and screening can be compulsory, whether marriage and childbearing of patients with severe genetic diseases should be restricted, whether genetic information should be kept confidential, whether genetic counseling services should be free, and how to weigh the advantages and disadvantages brought by these technologies. How is the application of genetic technology to reduce the number of patients with genetic diseases and improve the quality of the population different from the so-called eugenics movement advocated by Nazi Germany in purpose and mode?

6. Death and euthanasia. Due to the development and application of life support technology, medical staff can keep brain-dead patients and persistent vegetative patients in irreversible coma alive, but they will never lose consciousness and motor ability. This makes people feel that it is necessary to reconsider the concept of death and redefine it. Many countries have legally recognized the concept of brain death. But the concept of brain death is the concept of total brain death. The hot question is: Is the persistent vegetative person whose cerebral cortex is dead but whose brain stem is still alive dead? On the other hand, can a brainless child be considered a human being? The death mentioned here is the death of people, so the concept of death is closely related to the concept of what people are. If brain-dead, vegetative and anencephaly are considered dead, it is not within the scope of euthanasia not to treat them or take measures to end their lives. The ethical issue of euthanasia is the most active and controversial issue in medical ethics. Voluntary passive euthanasia, that is, according to the requirements of dying patients, not giving him treatment or withdrawing treatment, has been recognized by the laws of many countries, and patients with incapacity can also make decisions by agents. However, there are still different opinions on whether artificial water supply and feeding should be included in the treatment that cannot be given or removed. There is a great controversy about active euthanasia, mainly because there are still different opinions on whether there is a qualitative difference between the active behavior of ending patients' lives and the passive behavior of not giving or withdrawing treatment. In the case of active euthanasia, it is difficult to determine whether the cause of death is disease or action, and whether the person taking action is out of goodwill or malice. Euthanasia also involves the treatment of severely disabled newborns, that is, what criteria should be used to make decisions and who should make decisions. Opposing euthanasia can be based on morality and consequences. For example, euthanasia killing innocent people may have a negative effect on the moral responsibility of medical staff and the development of medicine.

⑦ Distribution of medical and health resources and health policies. Resource allocation includes macro resource allocation and micro resource allocation. The macro distribution of medical and health resources refers to how much of all available resources in the country should be allocated to medical and health care and how the resources allocated to medical and health care should be distributed among medical and health departments, such as how much cancer research should be divided, how much preventive medicine should be divided, and how much high-tech medicine should be divided. Macro distribution must also solve the following problems: whether the government should be responsible for medical and health care, or leave medical and health care to the market, and if the government should be responsible, how much budget should be used for medical and health care. How to make the most effective use of the budget allocated to medical and health undertakings, such as whether the budget should focus on rescue methods such as kidney dialysis, organ transplantation and intensive care, or on disease prevention; Which diseases should be given priority in resource allocation; And how much resources the government should invest to change individual behavior patterns and lifestyles (such as smoking); Wait a minute. Micro-distribution of resources refers to the principles by which medical staff and medical administrative units allocate health resources to patients and how to allocate them fairly and reasonably. When it comes to scarce resources, which patients can get the resources first (for example, two patients need kidney transplantation, but only one kidney can be transplanted). In order to carry out micro-distribution, it is necessary to stipulate some rules and procedures to decide who can obtain such resources, that is, to conduct preliminary screening according to indications, age, possibility and hope of successful treatment, life expectancy and quality of life. Then some rules and procedures are stipulated, and from this range, it is finally decided who will get this resource. The provisions of this set of rules and procedures often refer to social standards: the status and role of patients, past achievements, potential contributions, etc. However, there are many controversies about social standards.

The most controversial issue in health policy is whether a country should socialize health care, such as public medical care or medical insurance, or commercialize health care, or adopt a mixed compromise (for example, the basic needs of health care are the responsibility of the state, while high-tech drugs are purchased by patients according to their income).

The remarkable characteristics of medical ethics are practicality, inheritance and times.