The pathophysiology of human immunodeficiency virus (HIV) is complex. The etiology of headache in the HIV population is often multifactorial, and attributing causality to specific pathophysiological mechanisms is challenging. Headaches can occur any time during the infection and may be primary (as in non-HIV-infected patients) or secondary (either from HIV directly or due to opportunistic disease).
Direct HIV related headaches are due to the underlying viral pathophysiology. For example, acute meningitis can be seen during HIV-1 seroconversion. Headaches can occur during symptomatic HIV and also after an AIDS-defining illness. Late-stage HIV headache can occur without any pleocytosis. A correlation between viral load and neurological symptoms including headache has been suggested. There may be similar mechanisms involving migraine, tension-type headache, and HIV infection.
Secondary HIV headaches can be related to opportunistic infections, malignancy, medications used to treat HIV, and immune restoration inflammatory syndrome.