Answer:
When using illegal drugs, the risk of catching certain infectious diseases increases because drug use can weaken the immune system and impair judgment, leading to risky behaviors that increase the likelihood of exposure to infectious agents. Injecting drugs with shared needles or other injection equipment can also increase the risk of transmission of blood-borne pathogens such as HIV, hepatitis B, and hepatitis C. In addition, drug use can lead to poor hygiene, inadequate nutrition, and unsafe sexual practices, which can further increase the risk of infectious diseases. Finally, drug use can also lead to social isolation, homelessness, and other factors that can make it harder to access health care and other resources that can help prevent and treat infectious diseases.