Every author gets rejected. What to do with a rejection can be challenging. Do you revise or immediately resubmit elsewhere? The answer depends mostly on what sort of reasons you were (or were not) given for a rejection.
Immediate rejection is usually due to one of a couple of reasons. The first and most common is related to the topic of the paper or how a study was conducted: the topic doesn’t completely fit the focus of the journal to which it was submitted, it isn’t timely or novel, or methods are questionable. Less often, papers can be rejected outright due to formatting or writing issues: the paper isn’t formatted according to the journal’s instructions, the writing is poor or incomprehensible, elements such as figures or tables are simply missing, or the paper is not “clean,” in that there are tracked changes or comments that have not been addressed and removed.
Hopefully the journal provided some comments for the immediate rejection. If not, you can certainly email and ask (kindly) for a reason, stating that you are seeking feedback to improve the next draft.
If your paper was rejected after peer review, first and foremost, consider reviewer or editor comments objectively and revise the paper accordingly, even if you ultimately submit to another journal. Many reviewers spend substantial time addressing issues they see in your paper, so it’s always wise to carefully consider what they have stated. It is important not to take comments or suggestions personally. If you don’t agree with a reviewer’s suggestion, it might be best to explain in a revision why you did or did not do something as the reviewer suggested. Remember, even when a manuscript is resubmitted to a different journal, it will be reviewed by those in the same area of expertise; your paper may even be reviewed again by the same reviewer! (I have seen this happen.)
If you do submit to a different journal, remember to reformat according to the next journal’s instructions! If the paper was originally formatted for Journal A, read the instructions for formatting for Journal B. If you don’t reformat, the editorial office of Journal B will see that your manuscript was not formatted for Journal B and quickly intuit that it was likely rejected elsewhere. Or you just didn’t take the time to read their instructions and format it properly. Either way, this immediately creates an unfavorable impression.
There are a number of articles and blog posts explaining why health science manuscripts are rejected, many written by editors and experienced reviewers. Most report the same general reasons, but here are a few that I find helpful.
If this article from 2014 by a health science editor at Elsevier doesn’t convince you that following a journal’s instructions are important, nothing will. Confessions of a managing editor (or 6 reasons I’m returning your manuscript)
From Research Medics: Top Ten Reasons Papers Get Rejected
From Nature publications: How to bounce back from a bruising peer-review or paper rejection
Finally, some interesting opinions on a ResearchGate blog: What are the most popular reasons editors usually reject your paper for?
As always, feel free to contact me with any manuscript questions at email@example.com.