Generally speaking, there is no 'standard' in terms of phrasing emergent themes of your data. Styles and lengths of your themes should really depend on your conceptual framework or key theories applied to your research. emergent themes should reflect your concept and hence you can certainly consider to adapt a similar structure of managing your emergent themes.

Dear researcher'

Theme identification is one of the most fundamental tasks in qualitative research. It also one of the most mysterious. Explicit descriptions of theme discovery are rarely described in articles and reports and if so are often regulated to appendices or footnotes. Techniques are shared among small groups of social scientists and are often impeded by disciplinary or epistemological boundaries. During the proposal-writing phase of a project, investigators struggle to clearly explain and justify plans for discovering themes. These issues are particularly cogent when funding reviewers are unfamiliar with qualitative traditions.

Please read this articel to find some important techniques in phrasing themes

http://www.analytictech.com/mb870/readings/ryan-bernard_techniques_to_identify_themes_in.htm

Good luck

If you have already found the general content for the themes and now your goal is to put them into words, then the most important consideration is the ability of your reader to easily understand what you are saying. I recommend to my students that they summarize each theme in a single brief sentence, or better yet, a strong phrase.

Also, it is important not to have too many themes, since it becomes hard for the reader to keep them all in mind. If you have more than five or so themes, re-examine them to see if some of them can fit together as sub-themes for a larger key theme.

Dear Hulya,

There are no rules for naming emergent themes from a qualitative research. However, it is a standard practice to use words that are appropriate - convey the exact meaning that you intend for the readers, and easier to understand, if possible.

As long as it is still a phrase and not a sentence, the length should not be an issue. Just keep it as short and precise as possible.

The following sources may also help: 

• Attride-stirling, J. (2001). Thematic networks: an analytic tool for qualitative research. Qualitative Research, 1, 3, pp. 385-405.
• Bazeley, P. (2009). Analysing Qualitative Data: More Than ‘Identifying Themes’. The Malaysian Journal of Qualitative Research, 2, 2, pp. 6-22.
• King, N. (2004). Using Templates in the thematic analysis of text. In: Cassell, C. andSymon, G. (eds.) Essential guide to qualitative methods in organizational research. London, Thousands Oaks: SAGE Publications, pp. 256-270.
• Thomas, D. R. (2006). A General Inductive Approach for Analyzing Qualitative Evaluation Data. American Journal of Evaluation, 27, 2, pp. 237-246.