Algolagnia (/ælɡəˈlæɡniə/; from Greek: ἄλγος, álgos, "pain", and Greek: λαγνεία, lagneía, "lust") is a sexual tendency which is defined by deriving sexual pleasure and stimulation from physical pain,[1] often involving an erogenous zone. Studies conducted indicate differences in how the brains of those with algolagnia interpret nerve input.[1]