When someone cannot speak while choking, the airway is blocked and the immediate goal is to relieve that blockage. Abdominal thrusts push air from the lungs upward, creating pressure that can expel the obstructing object from the airway. This direct action addresses the problem right away and is the most effective first response for a conscious adult who is choking. Chest compressions, on the other hand, are used for cardiac arrest and won’t clear a blocked airway; attempting them while the object remains lodged can be ineffective and even harmful. Checking for a pulse isn’t the priority during a choking emergency because you need to act to clear the airway first. If you’re alone, call emergency services right away and continue attempts to dislodge the object; if the person becomes unconscious, transition to CPR and call for help.

HIV is a virus that attacks and weakens the immune system. It targets the body's CD4 T cells, which helps explain why infection with HIV can undermine the body's defenses and lead to increased susceptibility to other illnesses. This virus is primarily transmitted through sexual contact, as well as through sharing needles or from mother to child, which is why it’s described in many materials as an STD. It is not a parasite that causes digestive problems, and it is not a bacterial skin infection. Antibiotics target bacteria, not viruses, so HIV cannot be cured with a single antibiotic. There is no cure yet, but antiretroviral therapy can suppress the virus, helping the immune system recover and allowing people with HIV to live long, healthy lives.

Understanding how HIV progresses helps explain why the late stage is called AIDS. HIV damages the immune system by targeting CD4 T cells. When those cells drop to very low levels or the body develops opportunistic infections or certain cancers, the immune system is too weak to fight off illnesses, and this advanced stage is diagnosed as AIDS. The other terms listed refer to distinct infections or diseases that can occur in people with HIV or are unrelated conditions (hepatitis affects the liver; tuberculosis is a bacterial infection; herpes is a viral infection), but they are not the label for the final stage of HIV.

Bacteria are single-celled organisms that can cause infections. Tuberculosis is caused by a bacterium, Mycobacterium tuberculosis, so it is a bacterial disease. Malaria is caused by a parasite (Plasmodium) transmitted by mosquitoes. Ringworm is a fungal infection caused by dermatophyte fungi. Polio is caused by a virus. Recognizing the type of organism behind a disease helps explain why certain treatments work (antibiotics for bacteria, antivirals or vaccines for viruses, antifungals for fungi, antiparasitics for parasites).