I have been suffering from an illness for a long time. Please advise me what should I do. Would reciting Chapter Yaseen be useful for me?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.

We pray to Allaah The Almighty to cure you and grant you, and all Muslims, good health. You should know that the Prophet, sallallaahu ‘alayhi wa sallam, told us that Muslims are rewarded for any fatigue, disease or distress that befalls them, because this acts as an atonement for their sins. [Al-Bukhari and Muslim]

You should consult specialist physicians because Allaah The Almighty has created a cure for every disease -- it may be known to one but unknown to others.

Moreover, you should see someone who can perform Ruqyah (healing with the Quran and Prophetic supplications) who will recite the Quran, invocations and supplications for you, although it would be better if you perform Ruqyah for yourself. In fact,  Chapter Yaseen does not have any specific advantage over the other Chapters of the Quran, because the entire Quran is a cure. However, among the recommended Chapters and verses are: Chapter Al-Faatihah, the verse of Al-Kursi [Quran 2:255], the last two verses of the Chapters Al-Baqarah, Al-Ikhlaas, Al-Falaq and An-Naas.

Moreover, you should always seek refuge in Allaah The Almighty and invoke Him repeatedly, and you should be satisfied with what Allaah The Almighty has predestined for you. Remember that a Muslim who accepts an affliction will be content and Allaah The Almighty will be pleased with him, otherwise he will be discontent and Allaah The Almighty will be displeased with him.

We ask Allaah The Exalted to cure you and all ailing Muslims.

Allaah Knows best.