Cancer is a group of many different diseases with many different treatments, involving many different parts of the body, all with the common problem of uncontrolled growth. For some reason, a single cancer cell loses the ability to grow in an organized, controlled fashion, and starts to grow out of control. Depending on how quickly and where the cells grow, symptoms of disease then develop. Most of our doctors are also hematologists, specialists in disorders of the blood. While hematologists treat malignancies of the blood like leukemia and lymphoma, they also treat all the non-malignant blood diseases like anemias, low platelet counts, and bleeding and clotting disorders.
Chemotherapy is medicine that treats cancer.
Every cancer has its own combination of medicine that works best for it. Breast cancer chemotherapy will not be the same as lymphoma chemotherapy. Comparing your friend's or relative's reaction to their chemotherapy will likely be different from yours, as you are probably getting different things. Most patients do not vomit after their chemotherapy. Most patients do not experience nausea after their chemotherapy.