What condition can weaken the immune system and increase the risk of infection?

HIV/AIDS is a condition that significantly impacts the immune system, specifically targeting and destroying CD4 cells, which are crucial for a healthy immune response. When the number of these cells decreases, the body becomes less capable of fighting off infections and diseases, leading to an increased susceptibility to opportunistic infections and other health complications.

In contrast, while diabetes can lead to immune system impairment due to factors like high blood sugar levels, it does not have the same direct and profound effect on the immune system as HIV/AIDS. Hypertension primarily affects cardiovascular health and does not directly weaken the immune response. Asthma, while a respiratory condition, does not compromise the immune system in a way that would lead to increased infection risk related to immune deficiency. Therefore, HIV/AIDS is the condition that most clearly and directly leads to a weakened immune system and a higher risk of infections.