Immune deficiencies occur when the body's immune system is unable to effectively fight off infections and diseases. This can happen due to genetic factors, certain medical conditions, or the use of specific medications. People with immune deficiencies may experience frequent infections, delayed recovery, and increased susceptibility to illnesses. There are two main types of immune deficiencies: primary immune deficiencies, which are usually inherited and present at birth, and secondary immune deficiencies, which can develop later in life due to factors like HIV/AIDS, malnutrition, or chemotherapy. Understanding these conditions is crucial for proper diagnosis and treatment.