Aspirin nsaid is a common over the counter anti-inflammatory drug that is mostly used to relieve pain. Aspirin nsaid is also used for fever reduction. This drug works by preventing the formation of a substance called prostaglandins. This is a chemical that is known to cause swelling, fever, blood clot and increased body pain. When our body produce too much prostaglandins, this might result to increased body pain, swelling and discomforts incase of an external injury.