Prostate cancer is prostate cancer. Generally speaking, prostate cancer will die of multi-organ failure by the final time of the disease, which is mainly determined by the fact that prostate cancer has the characteristics of organ metastasis. Depending on the organ failure, different symptoms will appear in the first three days of death. The most common metastasis of prostate cancer is pulmonary metastasis, and three days before death, there may be gradually increasing pleural effusion in the lungs and organ compression and irritation symptoms from the metastases in the lungs. Dyspnea, cough, sputum, and coughing up blood may occur due to the reduced breathing area. Patients will develop respiratory failure and carbon dioxide encephalopathy, causing drowsiness, coma, decreased oxygen saturation, and other symptoms. Bone metastases can also occur in prostate cancer and may be at the most severe stage of the disease three days before death. It can lead to more severe and unbearable bone pain, a pain that is hardly effective with the usual analgesic drugs. Prostate cancer itself causes an increase in the size of the prostate gland, which may result in a complete blockage of the urinary tract and the inability to urinate. Prostate cancer itself is a malignant disease, especially before death there will be a relatively large number of organ metastases, thus aggravating the poor nutritional status caused by malignant tumors, causing symptoms such as anemia, extreme fatigue, and extreme body wasting. In conclusion, the main symptoms of prostate cancer three days before death are related to the specifics and severity of advanced prostate metastasis, in addition to showing some nutritional status problems specific to malignant disease.