Understanding the Immune System The immune system is a collection of different cells, tissues, and organs that work together to protect the body from infections or other foreign substances. Learning more about it might help you feel more comfortable if you have a health condition because it can help you better understand what could be wrong. The immune system has two different types of responses: innate immunity and adaptive immunity. The natural immune system protects against bacteria and fungi while the adaptive immune system fights viruses. Other triggers activate the cells that make up each type; this is important for protecting the body from harmful invaders as these triggers can vary by infection. Immune cells are either lymphocytes or phagocytes and are responsible for fighting disease. The immune system also protects against cancer. Cancer occurs when cells in the body grow out of control and form tumours. The immune system detects abnormal cells and destroys them before they can spread. The body has two main types of white blood cells that fight cancer: B lymphocytes, which make antibodies that can destroy abnormal cells, and T lymphocytes, which release chemicals to kill infected cells. Each immune system response is tailored to work best against its specific target. When it comes to allergies, people often refer to the immune system as a single entity that overreacts to substances that it perceives as threatening. An immune system is a group of organs, cells, and senses that protect the body from foreign substances. While this system may be overactive in people with allergies, these people are not immune-deficient. The immune system must react quickly and efficiently to potential threats to protect the body. However, this system may be over-reactive when allergic reactions—for example, if a person has asthma caused by an allergy. The Immune System May Help Fight Infectious Diseases The human body lives in a world inhabited by millions of organisms that could potentially cause disease. While we may not even see these organisms with the naked eye, they are present in our bodies and on our skin every day. These organisms are so tiny that a microscope is needed to view them. While many are beneficial to the body, some cause infections or illnesses. The immune system is the collection of cells and organs responsible for protecting the body from these harmful organisms by destroying them or preventing them from damaging the body. This defence system acts as the first line of defence against viral and bacterial infections that can spread throughout the body if left untreated. The immune system can be divided into two parts: innate and adaptive. The natural immune system fights off infections before they can do any damage. Without an innate response, an infection could become too widespread to prevent. The adaptive immune system becomes activated after the innate immune system has successfully cleared away the initial infection. This part of the immune response is what is referred to as an allergic reaction, or when a person's body reacts against something that it thinks is a threat and tries to destroy it using antibodies that are produced in the body and secreted into fluids surrounding the body such as blood, urine and saliva. While antibodies exist in all humans, those with allergies tend to have more of these proteins circulating in their bodies than others. The number of toxins in the body and their level of sensitivity can also play a role in whether an individual begins to experience allergic reactions. Common Causes of Allergies Infectious diseases, such as measles and chickenpox, are common causes of allergies. However, several other issues can cause allergies as well. In the case of someone who does not have a robust immune system, the immune system may be unable to respond effectively to this infection or allergy because there are not enough cells or enough resources being produced by these cells when needed most to fight off the infection or allergens. You may be more susceptible to certain illnesses or allergens than others, depending on your health condition. With the introduction of vaccines to help prevent people from getting certain types of infections, people began to think that the only reason they had ever called them before was that they did not have a vaccine. So if they had been vaccinated and still got sick, it must be because their immune systems were not functioning correctly. This is not entirely true, as there are many different reasons that a person might get sick with an infection or develop allergies. Genetics plays a significant role in how your immune system reacts to infections or allergies. If your parents had an allergic condition, then you may be more likely to develop one as well.