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, often involving an erogenous zone. Studies conducted indicate differences in how the brains of those with algolagnia interpret nerve input.