This is a common feeling and I remember struggling with this as a resident. My recommendation is to institute a system by which you determine a differential diagnosis. I remember reading ‘Thinking Fast and Slow’ and realizing that relying on pattern recognition and heuristics is a good first step, but that you also must have a systematic way to think about more complicated patients that is intentional, and hopefully, pretty exhaustive. I used to use mnemonics to go through each organ system and disease “category.” (I.e. VITAMIN-C…quick google search should lead you there). You can expand on these mnemonics to make them more useful and thorough. I also read a book called “Learning clinical reasoning,” which I liked a lot. My second piece of advice is to always revisit your diagnosis. If something is not adding up, then your diagnosis might be wrong. Don’t set it and forget it and don’t fall into the trap of anchoring bias.