While our bodies may be resilient, there is a certain balance that it must maintain to stay functioning well and healthy. Too much or too little of something can throw that balance into disarray. This can cause problems ranging from something relatively simple to deal with like acne, to long-term conditions, like rheumatoid arthritis. There are also some cases that can, unfortunately, become fatal due to diseases like the various forms of cancer. This is where chemotherapy comes in. The different types of Chemotherapy drugs curb or cull unwanted, accelerated growth of whatever cells are causing problems in our bodies.