Some people feel as though they have the flu for a few hours to a few days after chemotherapy. This may be especially true if you are receiving chemotherapy in combination with biological therapy. Flu-like symptoms — muscle and joint aches, headache, tiredness, nausea, slight fever (usually <100F), chills, and poor appetite — may last from 1 to 3 days. An infection or the cancer itself can also cause these symptoms. Check with your doctor if you have flu-like symptoms.