Medicine is one of the oldest branches of science. People have always been seeking means to alleviate sicknesses and prolong life. In olden times, people achieved this by taking resources, like plant and animal parts, from nature. Other times, they observe the healing techniques of sick animals. Most striking of all is shifting to a certain type of lifestyle in the hopes of alleviating disease. A few decades ago, advances in the study of chemicals and a greater understanding of how the human body works has prompted the wide use of drug-based medications. Because of their efficacy, many previously life-threatening diseases (like fevers) can be easily resolved. However, researchers, physicians, and lay people alike have noticed that negative side-effects sometimes come with these medications.