Although a dose of just 25 rems produces some obvious changes in blood. Doses higher than 100 rems cause the first signs of radiation sickness including: nausea, vomiting, headache and some loss of white blood cells. Doses more than 300 rems cause temporary hair loss and significant internal injury, including damage to the cells that line the digestive tract and nerve cells. Severe damage of white blood cells, which are the main defense against infection, makes radiation victims susceptible to disease. Also, radiation reduces production of blood platelets, which involved in blood clotting, so victims of radiation sickness are at risk of hemorrhage. Doses of 450 rems may lead to death, and doses of 800 rems or more are always fatal. Also the symptoms may include fever and diarrhea. There is currently no effective medical treatment available for potentially fatal radiation doses. So death occurs within two to fourteen days. The concerns pointed to protect against lethal radiation exposure, therefore, expert introduce EX-RAD as a drug, which protects and repairs DNA after radiation exposure.