There are still many reasons for hiccups in cancer patients, most of which are due to hiccups caused by poor digestion, also known as the erratic reaction. Most hiccups are caused by poor digestion, or erratic reactions. Normal people, even those who are not cancer patients, may have hiccups if they eat something cold or have indigestion. There is also the case of cancer patients with metastatic tumors in the diaphragm, which can also cause hiccups or persistent erratic reactions that are more difficult to treat. Cancer patients may develop multiple metastases as their disease progresses. The presence of hiccups also depends on what treatment the patient is undergoing. If the hiccups are sudden and unexplained, the possibility of diaphragmatic metastases needs to be considered. In other cases, cancer patients who have chemotherapy that triggers nausea, vomiting and other gastrointestinal reactions can also cause hiccups, and require intensive antiemetic and sedative medication.