# Use of X in Medical Abbreviations (or Ux of X in Mx Ax) **URL:** \ **Category:** Factual Questions\ **Created:** [June 18, 2007, 7:53pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500 "2007-06-18T19:53:43Z")\ **Posts on this page:** 15\ **Page:** 2
**Author:** ![Malodorous](https://avatars.discourse-cdn.com/v4/letter/m/e47774/32.png) [@Malodorous](https://boards.straightdope.com/u/Malodorous)\ **Post date:** [June 19, 2007, 3:32pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/21 "2007-06-19T15:32:38Z")
[QUOTE=Cub Mistress] Some of the X-style abbreviations have more than one meaning, it all depends on context. It drove me crazy my first semester in nursing school, because it was never explained. I’ve seen bx to mean biopsy, behavior or bilateral (that was only one time and may have just been that nurse’s idea of a great abbreviation.) [/QUOTE] The hospital near my house recently said they wouldn’t accept doctors test orders with abbreviations because they weren’t standardized and so caused too much confusion. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [June 19, 2007, 8:10pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/22 "2007-06-19T20:10:43Z")
[QUOTE=athelas] No; Ixians made machines. [/QUOTE] Per the canonical book, yes. Per Lynch’s film, IX was home to mentats. ---
**Author:** ![Gestalt](https://avatars.discourse-cdn.com/v4/letter/g/90ced4/32.png) [@Gestalt](https://boards.straightdope.com/u/Gestalt)\ **Post date:** [June 20, 2007, 3:28am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/23 "2007-06-20T03:28:57Z")
[QUOTE=Qadgop the Mercotan] Dx: Diagnosis No, I don’t know why these were picked. [/QUOTE] This is probably going to sound reeaaallly stupid, but . . . I always wondered why diagnosis was abbreviated “Dx” as well. Then I heard primary diagnoses referred to as, “differential diagnoses.” Then I remembered that with a function of x, the derivates of a function are dx/dt (or whatever it’s being differentiated with respect to), d2x/dt2 (sorry, don’t know how to do the correct coding), etc. When you take the derivative of a function, you are said to “differentiate” it. So I wondered if the two were related. Any insight? Gestalt. ---
**Author:** ![The\_Stafford\_Cripps](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_stafford_cripps/32/7167_2.png) [@The\_Stafford\_Cripps](https://boards.straightdope.com/u/The_Stafford_Cripps)\ **Post date:** [June 21, 2007, 7:23pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/24 "2007-06-21T19:23:33Z")
Ax =Assessment Tx = Transfer (eg from bed to chair) ---
**Author:** ![Alan\_Smithee](https://avatars.discourse-cdn.com/v4/letter/a/2acd7d/32.png) [@Alan\_Smithee](https://boards.straightdope.com/u/Alan_Smithee)\ **Post date:** [June 21, 2007, 8:19pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/25 "2007-06-21T20:19:06Z")
Well we’re getting closer to developing the AMA Phonetic Alphabet, but even with Jill’s Staff Report on Rx, we aren’t any closer to finding the origin of any of these abbreviations. We don’t even know if they were influenced by Rx, parallel developments, or totally unrelated. Are they recent coinages, or do they originate in medieval texts? Jill’s Report suggests that Rx may have originated as an abbreviation for Latin _recipe_ formed by placing a crossbar over the tail of the R. Were any of these abbreviations formed that way? Were _any_ abbreviations formed this way? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [June 21, 2007, 8:34pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/26 "2007-06-21T20:34:27Z")
[QUOTE=Alan Smithee] (not that comprehensible matters for Mx Px [medical professionals]). [/QUOTE] Rx, what’s that? Rx, not quite yet! ---
**Author:** ![MobiusDick](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@MobiusDick](https://boards.straightdope.com/u/MobiusDick)\ **Post date:** [October 8, 2014, 2:39am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/27 "2014-10-08T02:39:38Z")
Rx always means therapy and much of the time, the therapy is pharmacologic, but may be physiologic or involve medical equipment. So we Rx things like Digoxin for CHF or congestive heart failure. It would be written take one tablet by mouth before eating in the morning and 1/2 tablet in the evenings by mouth before eating. Rx: Digoxin 500 mgs Disp # 45 for 45 Days . \_\_ Sig: T po ac qAM & ss po.ac qPM Or you could Rx: PT or OT or a CPAP Ex is equipment not example which is eg MobiusDick, MD, PhD ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [October 8, 2014, 2:49am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/28 "2014-10-08T02:49:20Z")
If a patient seeks treatment for erectile dysfunction, does that mean that they are asking for Tx for their Dx? Then the doctor tells them that they just need to stop Jx-ing so much. One time, a farmer got told that until he was willing to Nx the Ox Fx-ing, he would never have ordinary, satisfying Sx. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [October 8, 2014, 4:12am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/29 "2014-10-08T04:12:13Z")
> [@Cub\_Mistress](#): > > Some of the X-style abbreviations have more than one meaning, it all depends on context. It drove me crazy my first semester in nursing school, because it was never explained. I’ve seen bx to mean biopsy, behavior or bilateral (that was only one time and may have just been that nurse’s idea of a great abbreviation.) In my own medical records, I’ve likewise seen Bx, as used by psychologists, to mean behavior. I’ve also seen Ox in my records, but I never figured out what it stands for. In the context, it certainly wasn’t referring to O[sub]2[/sub]. Do we have an answer for that yet? ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [October 8, 2014, 4:24am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/30 "2014-10-08T04:24:38Z")
It wasn’t an abbreviation. They thought you were an ox. ---
**Author:** ![Gretchion](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@Gretchion](https://boards.straightdope.com/u/Gretchion)\ **Post date:** [October 8, 2014, 6:11am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/31 "2014-10-08T06:11:25Z")
There’s also Zx, which refers to zombie threads ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [October 8, 2014, 10:04am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/32 "2014-10-08T10:04:16Z")
One more instance of a common language causing problems: As far as I know, none of these abbreviations are used or recognised over here. Doctor’s bad writing and ad hoc abbreviations have, however, been causing problems since they first started writing prescriptions. ---
**Author:** ![Double\_Foolscap](https://avatars.discourse-cdn.com/v4/letter/d/85e7bf/32.png) [@Double\_Foolscap](https://boards.straightdope.com/u/Double_Foolscap)\ **Post date:** [October 8, 2014, 11:41am UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/33 "2014-10-08T11:41:15Z")
If you use X instead of an I, it means that the cartoon character is dead. ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [October 8, 2014, 12:47pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/34 "2014-10-08T12:47:50Z")
I wx that px who reopen zx thx would just fx ox. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 8, 2014, 5:43pm UTC](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500/35 "2014-10-08T17:43:38Z")
> [@Gestalt](#): > > This is probably going to sound reeaaallly stupid, but . . . > > I always wondered why diagnosis was abbreviated “Dx” as well. Then I heard primary diagnoses referred to as, “differential diagnoses.” Then I remembered that with a function of x, the derivates of a function are dx/dt (or whatever it’s being differentiated with respect to), d2x/dt2 (sorry, don’t know how to do the correct coding), etc. When you take the derivative of a function, you are said to “differentiate” it. So I wondered if the two were related. Any insight? > > Gestalt. No connection really between the mathematical & the medical here. A “differential diagnosis” is simply the process of deciding what the patient’s problem is by looking at the differences between normality, the patient’s current state, and the indicia of all the various diseases or injuries. Imagine a tree-shaped flow chart starting with high level questions like: is patient breathing?, conscious, bleeding, etc. The asking more detailed questions about whatever. Finally getting down into microminutae about different blood test values or genetic factors. The process of working down the decision tree using the evidence of the patient is the process of differential diagnosis. In other words, discover the correct diagnosis by eliminating all the other diagnoses which have different parameters than your patient has. In math of course, differentials are (simplifying mightily) about taking two nearby X values and their corresponding Y values then evaluating the ratio between X1-X2 (their _difference_) versus Y1-Y2 (their _difference_). No connection really beyond the high-level meaning of the word difference as embodying some sort of comparison. [Previous page](https://boards.straightdope.com/t/use-of-x-in-medical-abbreviations-or-ux-of-x-in-mx-ax/408500.md?page=1)