Antonyms for the phrase "doctor up" include terms like "neglect, worsen, damage, spoil, hurt, impair, ruin, and harm." While "doctor up" refers to the act of improving, fixing or adjusting something, antonyms suggest the opposite. For instance, "neglecting" is the complete opposite, it is to fail to take proper care or attention to something, while "worsening" means to make something worse than it already was. "Damage", "spoil" and "ruin" all suggest the idea of negatively affecting something, while "hurting" and "impairing" indicate the harm of something over time. These antonyms illustrate the importance of taking care of things and the negative impact of neglecting them.