Light red urine in the late stage of lung adenocarcinoma may be caused by tumor invading the urinary system, which causes hematuria; it may also be caused by other reasons, and the specific situation varies from person to person. Red urine in late stage of lung adenocarcinoma may be due to bladder or kidney metastasis in late stage of lung cancer, which may cause painless hematuria, or may be combined with infection and cause urinary tract irritation, such as frequent urination, urgency, pain in urination and so on. Urine routine, ultrasound, CT and other tests can be given. The light red color of urine can also be related to food, drugs, etc. Some patients can have light red urine when using red dragon fruit, etc. Also, some drugs can cause light red urine, such as epirubicin, pirenzolibizine and so on; If patients undergo chemotherapy or radiotherapy, it can cause chemotherapeutic or radiotherapy cystitis, which can cause symptoms of hematuria; in addition, chemotherapy can cause coagulation caused by blood clotting function, which can lead to abnormalities such as hematuria. If patients with advanced stage of lung cancer have reddish urine color, they must seek medical treatment in time, clarify the cause of disease and treat it in time, and should not delay the condition and use drugs indiscriminately.