What to know about chemotherapy in people with diabetes

Nausea, vomiting, reduced appetite, infection, and medicines such as steroids can shift glucose levels. Changes may occur even when usual meals and diabetes medicines have not changed. Dehydration can make glucose management harder, while low intake can increase the risk of low glucose with some treatments. The team may adjust monitoring, tablets, or insulin temporarily and may check kidney function, hydration, and wound healing.

Share your glucose targets, diabetes medicines, insulin doses, monitoring method, recent low-glucose episodes, and sick-day plan. Ask how often to check glucose on treatment days and after steroid doses. Keep fluids and suitable carbohydrate sources available if advised, and record readings with food, symptoms, and medicines. Do not stop insulin or other prescribed treatment without specific instructions, even if appetite falls.

Call urgently for persistent vomiting, inability to keep fluids down, confusion, fainting, severe weakness, trouble breathing, very high or very low glucose readings, or ketones when your diabetes team has told you to check them. Fever or signs of infection also need prompt medical advice during chemotherapy, especially with a wound or device.

Ask how steroids may affect glucose, which readings require a call, what to do when you cannot eat, who changes diabetes medicines, and how oncology and diabetes teams will share your results.