Sometimes a sick person changes his Hebrew name or adds to it.
Is there a problem (halachically or otherwise) with changing one's Hebrew name, for someone who is not sick? For example, he prefers a different name for whatever reason.
I am especially interested in halachic problems with this.
According to the Halacha a person has the right to change his name to whatever he or she likes.
But the Minhag is not to do so without a valid reason, and only after consulting a prominent Rabbi, due to many complications that could arise in result of that, and for other reasons as well.
source: Kobetz Ginas Verdim
One of the senior Rabbis in Israel - Rav Chaim Kanievsky (son of the famous Steipler Gaon) - occasionally changes people's names.
This is often done when their Biblical names come from wicked people - like Nimrod.
A friend of mine - a scion of a Rabbinic family - was told to change his name from Amir to Meir. (The reason given by Rav Chaim was that Amir was animal food; though we have not been able to find a source for this.)
We see in the Chumash that Hashem renamed Abram to Abraham and Sarai to Sara and Yaakov to Yisrael - even though they were not ill.
Other biblical figures also had multiple names. For example Moses - as mention on Wikipedia:
Moses' other names were: Jekuthiel (by his mother), Heber (by his father), Jered (by Miriam), Avi Zanoah (by Aaron), Avi Gedor (by Kohath), Avi Soco (by his wet-nurse), Shemaiah ben Nethanel (by people of Israel). Moses is also attributed the names Toviah (as a first name), and Levi (as a family name) (Vayikra Rabbah 1:3), Heman, Mechoqeiq (lawgiver) and Ehl Gav Ish (Numbers 12:3).
Conclusion: There does not seem to be a Halachic issue with changing one's name, but I have not found any primary sources for this assertion.
That said, I assume there are Halachic implications when changing one's name - like when writing Gittin - a Get has to have the accurate name(s) of both spouses to be valid.
The Mishna in Gittin 4:2 indicates that it was common practice for people to change their names to nullify a bill of divorce.
בָּרִאשׁוֹנָה הָיָה מְשַׁנֶּה שְׁמוֹ וּשְׁמָהּ, שֵׁם עִירוֹ וְשֵׁם עִירָהּ. וְהִתְקִין רַבָּן גַּמְלִיאֵל הַזָּקֵן שֶׁיְּהֵא כוֹתֵב, אִישׁ פְּלוֹנִי וְכָל שֵׁם שֶׁיֵּשׁ לוֹ, אִשָּׁה פְלוֹנִית וְכָל שׁוּם שֶׁיֵּשׁ לָהּ, מִפְּנֵי תִקּוּן הָעוֹלָם
