The Qur'aan is a cure for your heart and body
All of the Qur'aan is a guidance, cure, and mercy for the believers. Allaah says in the Qur'aan:
And We send down of the Qur'aan that which is healing and mercy for the believers, but it does not increase the wrongdoers except in loss.
[Qur'aan 17:82]
Say, "It is, for those who believe, a guidance and cure."
[Qur'aan 41:44]
Imaam al-Shawkaani (may Allaah have mercy on him) said:
اختلف أهل العلم في معنى كونه شفاء على قولين : الأول : أنه شفاء للقلوب بزوال الجهل عنها وذهاب الريب [ أي : الشك ] وكشف الغطاء عن الأمور الدالة على الله سبحانه
القول الثاني : أنه شفاء من الأمراض الظاهرة بالرقى والتعوذ ونحو ذلك
ولا مانع من حمل الشفاء على المعنيين "
انتهى من " فتح القدير "
(3 /362)
The scholars differ in regards to the meaning of the Qur'aan being a cure. There are two understandings.
The first understanding is that it is a cure for the heart. It removes ignorance and doubt and uncovers those things which serve as a means to recognizing [the existence of] Allaah.
The second understanding is that it is a cure for diseases by means of Ruqya.
There is nothing to prevent from both understandings to be held to be true simultaneously.
Sheikh Ibn Uthaymiin (may Allaah have mercy on him) said:
" تأثير قراءة القرآن في المرضى أمرٌ لا ينكر ، قال الله تعالى : ( وَنُنَزِّلُ مِنَ الْقُرْآنِ مَا هُوَ شِفَاءٌ وَرَحْمَةٌ لِلْمُؤْمِنِينَ وَلا يَزِيدُ الظَّالِمِينَ إِلاَّ خَسَاراً ) ، والشفاء هنا شامل الشفاء من أمراض القلوب وأمراض الأجسام "
انتهى من " فتاوى نور على الدرب " لابن عثيمين
The effects of the recitation of the Qur'aan when it is used as Ruqy for the person who is sick is a matter which cannot be denied. Allaah says in the Qur'aan:
And We send down of the Qur'aan that which is healing and mercy for the believers, but it does not increase the wrongdoers except in loss.
[Qur'aan 17:82]
Cure here includes cure for the diseases of the heart and the diseases of the body.
There are Hadiith which indicate that certain Suurahs of the Qur'aan have more merit than others, as well as more affect in achieving a cure from disease, such as Suurah al-Faatiha which is the greatest Suurah in the Noble Qur'aan, Suurah al-Ikhlaas which is equal to one-third of the Qur'aan, and Suurah al-FalaQ and Suurah al-Naas.
As any person with intellect will come to understand from the above evidences, the Qur'aan is a cure. It is a cure for your heart. It is also a cure for bodily diseases you have.
There are many hadiith which serve as evidence. The recitation of the Qur'aan has been used as Ruqya to cure an ill person. The Salaf would recite the Verses of the Qur'aan over water and drink it when they were ill.
However, to achieve maximum benefit from the recitation of the Qur'aan for the purposes of Ruqya you have to have firm belief [yaQiin]. You have to believe it is the Kalaam of Allaah. You have to believe it will cure by the Permission of Allaah.
Without this belief the results will be less than optimal. And no, this is not a placebo. A placebo would be if you were going to restrict it to yourself believing it will work.
If you recite the Qur'aan with firm belief that it is the Kalaam of Allaah and will cure by His Permission, and then blow over another person who is ill, he will be cured of his disease. Placebo does not have such an effect.