Side effects are symptoms that can occur as a result of the oncological treatment administered (e.g. radiotherapy), can vary from patient to patient and depend on a number of factors. Depending on the part of the body being treated, the following may occur: diarrhoea, loss of hair in the area being irradiated, urinary disturbances, stomatitis, difficulty swallowing, swelling, nausea and vomiting and changes in potency.