I will preface this by saying this is just MY opinion........Above all else....BE HONEST! If you have some sort of issue in the past or present be honest about it. A problem could very well arise later on that could cause problems. Say for example, you hurt your back in rough housing with friends when you were 13. You had minor treatment and physical therapy a couple of times, and have had no problems since. You check "no" to any back issues. While in ROTC, the Academy, or on Active Duty, you hurt your back again. They do MRI's and CAT scans with contrast and find a evidence of an old injury (and I am pretty sure it can be found). Now you have lied on a government form, and the government can separate you without any VA benefits. Not that it IS going to happen, but it could and is it worth the risk?
As mentioned above in this forum, there is no need to answer "Yes" to something you never had treated, has not bothered you since, or has never been "diagnosed", that is asking for additional work or possible problems. But any surgeries, documented injuries, or current problems should be discussed with your parents and maybe your family doc at length, before submitting the self history.
Be Honest, if it is not a problem now, either a remedial or a waiver will take care of it, but it will be in your record and you are covered (aggravation in service is considered to be service-connected and benefits will help). If it is serious enough to cause you to consider not reporting it because you don't want to bring it up, you risk problems down the road. Not always, but it could happen. We told both our sons' make sure everything is filled out right, we even mentioned wisdom teeth, a childhood allergy problem, and a minor ankle sprain....just so they would not have to worry in the future. They did the remedials, and were cleared in under a month. We all felt better not having to possibly explain later about something re-occurring. If you think the issue could be serious enough to even possibly effect your ability to perform your duties, either have it fixed or get it waived. Do you really want to enter the military if you are going to have problems serving?? There are tons of way to serve your country not in the military..