Over time the immune system loses the struggle to contain HIV and so symptoms develop. Symptomatic HIV infection is often caused by the emergence of opportunistic infections. The commonest problems include fever, respiratory infections, cough, tuberculosis, weight loss, skin diseases, viral infections, oral thrush, pain and lymphadenopathy. This stage is the WHO stages II and III depending on the particular OI seen. See appendix 1 and 2 for reference.