Physiological dysfunction (such as hormone imbalance, abnormal immune function) and genetic factors (such as the discovery of high-risk cancer families, genetic defects, HLA antigen typing and the correlation with some tumor diseases, etc. ) can be a driving condition for the occurrence of tumor diseases and an important cause of tumor occurrence.

The second main reason: environmental factors.

At present, it is considered that there are three most important risk factors in the environment: carcinogenic compounds, carcinogenic virus infection, ionizing radiation and ultraviolet radiation. Among them, carcinogenic compounds are harmful because of their universality. The sources of environmental carcinogens are: plants (ammonium nitrite, polycyclic aromatic hydrocarbons, etc. ); Microorganisms (aflatoxin, etc. ); Synthetic materials (aromatic hydrocarbons, aromatic amines and their nitro derivatives, heterocyclic compounds, N- nitro compounds, inorganic compounds, etc. ); Incomplete combustion or pyrolysis products (tail gas, waste gas, cigarette gas, etc.). ).

Three main reasons: physical factors.

Ionizing radiation causes various cancers. Long-term thermal radiation also has a certain carcinogenic effect, and metal elements such as nickel, chromium, cadmium and beryllium also have carcinogenic effects on human body. There are some tumor diseases related to trauma in clinic. Patients with osteosarcoma, testicular sarcoma and tumor often have a history of trauma. Another foreign body related to tumor diseases is parasites.

The main reason four: chemical factors.

What are the main causes of tumor diseases? The mechanism of chemical carcinogens causing human tumors is very complicated. A small amount of carcinogens can directly induce tumors after entering the human body, which is called direct carcinogens; After most chemical carcinogens enter the human body, they need to undergo metabolic activation or biotransformation in the body to become carcinogens with carcinogenic activity in order to cause tumors. This substance is called an indirect carcinogen. Radiation-induced tumors include: thyroid tumor, lung cancer, bone tumor, skin cancer, multiple myeloma, lymphoma and so on.