Radiation poisoning is the result of overexposure to lethal amounts of radiation. Though symptoms can vary dependent on the person in question, most are fatal. Daniel Jackson received a massive amount of radiation from stopping a naquadria test from destroying the capital city of Kelowna. The amount of radiation poisoning caused his body to begin bleeding out and resulted in his internal organs to shut down. He only survived by ascending with the help of Oma Desala. (SG1: "Meridian")