Most contemporary scholars and medical councils hold that smoking is haram, because of its proven harm and the command not to destroy oneself (4:29, 2:195) and that the Prophet ﷺ made lawful only the good things (7:157). Some earlier scholars, before the harm was known, called it disliked (makruh). Today the harm is clear, so avoiding it is the safer and sounder position.
¡Creyentes! No os devoréis la hacienda injustamente unos a otros. Es diferente si comerciáis de común acuerdo. No os matéis unos a otros. Alá es misericordioso con vosotros.
a quienes sigan al Enviado, el Profeta de los gentiles, a quien ven mencionado en sus textos: en la Tora y en el Evangelio, que les ordena lo que está bien y les prohíbe lo que está mal, les declara lícitas las cosas buenas e ilícitas las impuras, y les libera de sus cargas y de las cadenas que sobre ellos pesaban. Los que crean en él, le sostengan y auxilien, los que sigan la Luz enviada abajo con él, ésos prosperarán.
This is general information, not a fatwa. For your own situation, ask a qualified scholar.
Questions about halal and haram
Is smoking haram?
Most contemporary scholars and medical councils hold that smoking is haram, because of its proven harm and the command not to destroy oneself (4:29, 2:195) and that the Prophet ﷺ made lawful only the good things (7:157). Some earlier scholars, before the harm was known, called it disliked (makruh). Today the harm is clear, so avoiding it is the safer and sounder position.