Lying down and wanting to pee may be physiological, or it may be due to pathological reasons, such as urinary tract infections. 1. Physiological: If you drink too much water, alcohol, etc. during the day, afternoon or night, you will have the urge to pee, which is a matter of life habits. It may also be caused by excessive tension, emotional disorders and so on. 2. Pathological: It may be caused by urinary tract infections, such as acute pyelonephritis, acute cystitis and other causes of frequent urination, and often there is urgency, painful urination and other uncomfortable symptoms. Note: If the symptom of wanting to urinate when lying down occurs, it is best to go to the hospital for examination, to clarify the cause of the disease, targeted treatment.