If a woman will be harmed by staying with her husband because he mistreats her and argues with her a great deal, it is permissible for her to ask for divorce, because of the report narrated by at-Tirmidhi (1187), Abu Dawood (2226) and Ibn Maajah (2055) from Thawbaan (may Allah be pleased with him), according to which the Messenger of Allah (blessings and peace of Allah be upon him) said: Any woman who asks her husband for a divorce when it is not absolutely necessary, the fragrance of Paradise will be forbidden to her.
This hadeeth was classed as saheeh by al-Albaani in Saheeh at-Tirmidhi.
The words when it is not absolutely necessary mean when there is no extreme hardship that compels her to ask for a divorce.
But if it is possible to reconcile between them, reconciliation is better.
And Allah knows best.
Reproduced from Islam QA