LGV stands for lymphogranuloma venereum. It's a type of chlamydia bacteria that attacks the lymph nodes, which are an important part of your body's defence against infections.
LGV is very rarely seen in heterosexual men and women in the UK but cases are being seen among gay and bisexual men.
Antibiotics cure LGV with no lasting effects as long as the infection is treated early enough. Left untreated, LGV can cause lasting damage to the rectum that may require surgery.