Is a person obliged to seek treatment for his wife and finance her medical expenses
if she becomes ill, just as he is obligated to support and clothe her? Is there a definite Nas (Islamic text from the Qur’an or the Sunnah) that states this?
There is a disagreement between Fuqaha' (Muslim jurists) concerning the husband's obligation to finance the medical expenses of his wife if she becomes ill. Some of them consider it as obligatory as feeding and clothing her, while others do not consider it obligatory, which is the more correct opinion. He does this out of his noble manners and good companionship.
Ibn Qudamah said in his book "Al-Mughny": He (a husband) is not obliged to pay for the medicine and the doctor's fees (for his wife), because this is meant to fix the body, so it is not obligatory for him, just like it is not obligatory for a tenant to fix the destroyed parts in the house and to maintain it. The same applies to the fees of Hijamah (cupping) and phlebotomy. (Part No. 19; Page No. 261) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.