I feel a slight pressure when I urinate and once finished, I have the impression that it's not finished. What could this be?

It sounds like you may be experiencing symptoms of a urinary tract infection, especially if you have other symptoms like pain in the lower abdomen, pain when urinating, or frequent urination. It's important to seek medical attention promptly if these symptoms are present. If you don't have these additional symptoms, it may be worth scheduling an appointment to see if there is an issue with emptying your bladder properly. Certain medications could also be causing this sensation. If you have any further questions or concerns, don't hesitate to reach out to a healthcare professional for guidance.