Is raising one's voice at a sick father considered a form of disobedience (ʿuqūq) if the aim is to persuade him to visit a doctor out of fear of his health deteriorating?

It is not permissible to address one's father in a harsh tone, even if it is out of concern and fear for him. This may be considered an act of disobedience if the father is hurt by it. The duty is to address parents with politeness, gentleness, humility, and reverence. The son should strive to persuade his father to seek treatment gently and politely, and if he does not agree, he should ask someone whose words he accepts to speak to him about it.