Does high calcium in cancer cause loss of appetite?

Loss of Appetite is a common presentation of High Calcium in Cancer. Reduced appetite may develop alongside thirst, nausea, constipation, tiredness, weakness or confusion.

Cancer-related high calcium, also called hypercalcaemia of malignancy, happens when cancer changes how calcium is released from bone or handled by the kidneys. Too much calcium can affect the digestive system and brain, making food unappealing and causing nausea or constipation. Loss of appetite can also have other causes, including the cancer itself, treatment, pain, infection, dehydration or emotional strain, so the symptom alone cannot identify the cause.

Tell the cancer team or clinician about a new or worsening appetite change, especially if drinking is difficult, weight is changing, or you are passing less urine. They may review medicines, examine you and arrange a blood calcium test with kidney checks. Until you receive advice, take small sips regularly if you can, choose small nourishing meals, and do not start supplements or stop prescribed treatment without discussing it.

Seek urgent medical help for new confusion, unusual drowsiness, fainting, severe weakness, repeated vomiting, inability to keep fluids down, severe abdominal pain or very little urine. These can signal significant dehydration or a more serious calcium disturbance. If symptoms are sudden or severe, use emergency services rather than travelling alone.

Ask whether your calcium level and kidney function need checking, what may be contributing to the appetite change, which foods and fluids are suitable, and which symptoms should prompt same-day contact.