An STD (sexually transmitted disease) is, as the name suggests, an infection passed on from person to person through intimate contact. Transmission can happen through many forms including unprotected intercourse, oral sex and sharing sex toys.
STDs are also commonly referred to as STIs (sexually transmitted infections) and in years gone by were also known as as VD (venereal disease).
People who are sexually active are exposed to these infections.
Symptoms can come in many forms including itching, swelling and pain. However, some diseases show little or no symptoms, so a person maybe carrying an STD without even knowing.
The best ways to avoid catching an STD are to practise safe sex, talk openly to your partner about previous sexual experiences and consult a doctor for advice and a check-up.