Urinating a lot in advanced liver cancer is not definitively a good or bad thing. There are many reasons that can lead to polyuria, such as: drug polyuria, neurogenic polyuria, infection and other factors. 1. Pharmacological polyuria: patients with advanced liver cancer need to alkalize urine and excrete toxins quickly, at this time diuretics will be used to increase urine, and some medicines will damage renal tubules, resulting in tubular absorption problems and causing polyuria. 2. Neurogenic polyuria: if brain metastasis occurs in late stage, it will affect the urinary center of brain and cause polyuria. 3. Infection: after receiving treatment, white blood cells of patients with advanced liver cancer will be lowered, which will lead to infection in urinary system, and patients will have symptoms such as frequent urination and painful urination. In case of polyuria in advanced stage of liver cancer, please clarify the cause of disease first and then treat symptomatically to avoid adverse reactions.