STIs can have devastating effects on sexual, reproductive and general health. They can also lead to a number of complications. If left untreated chlamydia and gonorrhoea can cause damage to reproductive organs and result in long-term complications such as infertility. People can even die if certain STIs such as syphilis are left untreated, or if they have complications such as pelvic inflammatory disease in the case of chlamydia. Read More