Blood cannot confirm the diagnosis of cancer, but some indicators, especially tumor markers, can help diagnose the disease through blood tests. Blood test can clarify the physical condition, such as whether there is infection, anemia, abnormal coagulation, etc., thus helping to diagnose the disease; it can also assist in the diagnosis of cancerous diseases through the tumor marker test, but it is not a definitive diagnosis, and it needs to be combined with the imaging test and pathology test. Imaging examination mainly includes ultrasound, CT, MRI, etc., which can clarify the location and size of the lesion. Secondly, pathology examination is needed to determine the nature of the tumor by taking biopsy, and finally confirm the diagnosis of cancer. Malignant tumor is the abnormal proliferation of a certain tissue or organ in the body, and the diagnosis of cancer requires comprehensive examination, both morphological diagnosis and pathological diagnosis. Therefore, if you feel unwell, it is recommended to consult a doctor in time to clarify the cause of the disease and carry out treatment under the guidance of a professional doctor.