Heartbeat
"Eighty-four. Fine. Now your lungs."
"Eighty-four?"
"Your heart rate. Bit fast, but consistent to other times I've taken your pulse. Doesn't seem to be causing any bother but I've been keeping an eye on it."
"You've been keeping an eye on my heart rate."
"Well. It's consistently faster than average. Could be a symptom of something. I'd rather not miss anything that could have been caught if I'd kept an eye on your slightly abnormal heart rate. You know?"
"It's not - You always count it high?"
"Between eighty-two and eighty-four, yeah."
"That's never been marked in my medical charts."
"They don't mark your heart rate?"
"They don't mark that it's high."
"Hrm. It's not high when they check it?"
"If it were then they'd mark it that way wouldn't they? What use would they have for marking it as average when it's not?"
"No you're right...if they've already counted it, there's not much reason to mark it down wrong...But with your history I wouldn't be surprised by a heightened heart rate. They must be marking it wrong for some reason."
"Or it's usually not this high."
"Pft, yes, because your heartbeat only speeds up when I -...Oh."
"...Oh?"
"Your heartbeat only speeds up when I count it."
"It does no such thing, John."
"Sherlock I'm a doctor, I know how to read a pulse."
"Well then maybe they didn't."
"Sher."
"..."
"Increased heart rate around one person is a symptom."
"John."
"Dilated pupils."
"John."
"Quickened breathing."
"Joh-mfh."
"Mm..."
...
"...Alright. Yes. It only speeds up when you count it."