HIV under the microscope

In this section you’ll read about HIV in more detail, how it gets into cells, and what happens once it’s inside.

All about cells

To understand how HIV makes people sick you have to know a little about viruses and cells.

Like all living things, your body is made of cells. Cells are the building blocks of life. Even though they are too small to see without a microscope, cells are like microscopic factories—complicated places constantly buzzing with activity.

Your body has many different kinds of cells, each with a particular role in keeping you alive and healthy. For instance, red blood cells carry oxygen in the air you breathe from your lungs to other parts of your body. On the way back to your lungs they pick up carbon dioxide, which you breathe out.

Your blood also contains white blood cells, which are a vital part of your immune system. Their role is to recognize and destroy viruses and other germs that might harm you. When a person has an HIV infection, it is these white blood cells in particular that HIV infects and kills.