How long chemotherapy courses last varies between different cancer types, with some being given intensively over a fortnight, normally in hospital, and some over a period of months. These include the cells in the hair follicles, which is why cancer treatment is often associated with hair loss, although hair does regrow once treatment has ended. Other fast-dividing cells can be found in the stomach and bowel lining, which leads to nausea and diarrhoea. There are, however, drugs which help control this, and timing meals to avoid having a full stomach when the drugs take effect can also help in some cases. Other types of normal cell that can suffer are the blood cells.
Red cells are important to carry oxygen to keep other cells alive.
Other blood cells help stave off infection. As a result, chemotherapy patients may be more prone to infections, and find them harder to fight off. Hospitals will take regular blood tests to monitor the levels of different cells. This is called a full blood count. Generally, patients on chemotherapy can expected to have less energy than usual, or even feel extreme fatigue.