Doctor, when CD4 count is below 12 what does it mean ?

CD4 cells are a type of lymphocytes and they help in immunity. HIV attacks and destroys these CD4 cells. A CD4 count of below 12 is very low. This would mean that the person will have low immunity and is likely to suffer from a severe infection. Such infections could be by bacteria, viruses or fungi. A person with such a low CD4 count is also susceptible to developing certain forms of cancers. This person _must_ consult a doctor immediately to be treated.