The immune system is a very complex network of cells, tissues and organs that work together to defend the body against pathogens. Its two main components are: the innate immune system and the adaptive immune system. However, when this system is compromised, the body’s ability to defend itself is impaired, which can increase the risk of developing at least one of the more than 80 autoimmune diseases that affect a significant proportion of the world’s population. These illnesses can cause a range of symptoms, including pain, fatigue, rashes, nausea, headaches and dizziness. They can also affect different parts of the body, such as the skin, muscles, joints, tendons, blood and blood vessels, and even other organs. Also, it is not uncommon to suffer from more than one type of autoimmune disease, as they share similarities in their basic immunological mechanisms. In this review, we aim to provide a more comprehensive understanding of the impact and severity of immune dysfunction. We will also describe the advantages and disadvantages of factors considered to promote immune function and summarize current knowledge about the mechanisms of certain autoimmune diseases. We hope to shed light on this complex subject and provide valuable insights into potential treatments and preventive measures for these diseases.