The phrasebooks are great, but what good will they do you if you do not understand the response to your question? There are courses taught at tech or community colleges which are very helpful. Look for a "Spanish for the healthcare provider" course. It will help you with the questions AND understanding the answers, but remember not all hispanics are speaking Spanish (Castillian) they may be speaking Portugese, etc... Sound similar to the untrained ear, but they aren't interchangeable. Think in terms of English as spoken in England, and English (however *******ized) in Brooklyn. The same language technically, but worlds apart linguistically.
About the best off the cuff Spanish I can toss to you is, "Donde dolor?" literally "Where is the pain?" but I prefer, "Un cerveza mas frio por favor."