Chemotherapy is the group of cell destroying drugs also known as cytotoxic drugs which kill the tumor cells.
Cytotoxic drugs are injected into our blood so that they can travel throughout the body. These drugs primarily affect very active (rapidly dividing) cells therefore along with the destruction of tumor cells, they kill some healthy cells also.
For example, our hair, skin, blood cells keep on following the cycle of birth & death so that they get affected due to chemotherapy. Hence patients suffer from hair loss, skin changes and poor cell count as side effects of chemotherapy.
Chemotherapy is given in cycles where a definite gap is scheduled before the next dose. These gaps depend upon the type of chemotherapy used & the tolerance of the patient.
There are forms of chemotherapy drugs which can be given in the form of pills. Oral chemotherapy is also offered when combined chemotherapy and radiotherapy is used as treatment option.