Should I mention this health issue I had on my graduate school application? Towards the end of one particular semester, I had some health issues which forced me to travel in order to get treated. This resulted in me missing the last two weeks of courses and all my final exams. I arranged so that I got grades of "incomplete" in all my courses, until I took the exams and finished my coursework after my recovery. I ended up doing okay, but I did get a B+ in a very important course. It's hard to say whether this was the reason for that, though. Should I mention this on my graduate school application, or will it look like I'm just making excuses?
I think it is worth mentioning.  Of course, you don't need to say "my health issues caused a B+".  Just mention the health issue at that particular time, and what you had to do to complete your work.  

Besides explaining your performance that semester (and a single B+ isn't very much to worry about), this shows your ability to overcome adversity and still succeed.  

Here are some other questions about explaining lower grades for non-academic reasons, and the answers largely seem to agree that it is a good idea to mention the circumstances:

Will one &#39;C&#39; grade due to health issues ruin my chances of admission into a top grad school?

Trauma affected my grades while in undergrad, how will it affect me getting into graduate school?