Immune system or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, and systemic lupus erythematosus. Immunology covers the study of all aspects of the immune system. Immunology is a science that examines the structure and function of the immune system. It originates from medicine and early studies on the causes of immunity to disease. The earliest known reference to immunity was during the plague of Athens in 430 BC. Thucydides noted that people who had
Behavioral immune system prototypical human being. The disease–avoidant processes that characterize the behavioral immune system have been shown to contribute to prejudices against obese individuals, elderly individuals, and people with physical disfigurements or disabilities. In addition, the behavioral immune system appears to contribute to xenophobia and ethnocentrism. One implication is that these prejudices tend to be exaggerated under conditions in which people feel especially vulnerable to the potential transmission of infectious diseases. Additional lines of research on the behavioral immune system have shown that people engage in more reticent and conservative forms of behavior under conditions in which they feel more vulnerable to