Remaining free of sexually transmitted infections is important for everyone’s health, but it is especially important if you have HIV. This is because sexually transmitted infections can not only cause illness (in some cases, more so in people with HIV), but also increase the risk that you will pass on HIV during unprotected sex, even if blood tests show that you have an undetectable viral load. Sexually transmitted infections can raise the amount of virus in your sexual fluids to a very high level, possibly making you much more infectious. There’s more about this in the section on undetectable viral load and infectiousness.

Although sexually transmitted infections other than HIV can seem a minor issue, they can and do cause unpleasant symptoms. If left untreated, some can cause severe health problems. In the very long term, some can cause irreversible damage to your health or, in extreme cases, be fatal.

Some sexually transmitted viral infections, such as herpes simplex virus (HSV, normally just called herpes), and HIV, of course, cannot be cured, although their symptoms can be reduced or treated.

Hepatitis B is very easily passed on during sex, and hepatitis A and C can also be transmitted during sex. Hepatitis A, B and C can make you ill in the short term, and hepatitis B and C can both cause long-term liver disease, which can make you very ill. Liver disease caused by these two viruses is now a major cause of death in people with HIV (see NAM’s booklet HIV & hepatitis for more information on hepatitis).

In some cases, people have been reinfected (this is sometimes called superinfected) with different or drug-resistant strains of HIV. There’s more on this in the section on reinfection.