What is Ruqya

Exorcism in Islam is called Ruqya, on the other hand summons jinn and demons by invoking the names of God, and to command them to abandon their mischiefs, and is thought to repair damage believed caused by jinn possession, witchcraft (shir) or the evil eye.
Exorcisms today are part of a wider body of contemporary Islamic alternative medicine called “prophetic medicine”.

Belief in Jinns, and other supernatural beings, is a requirement of Muslims. Jinn is an Arabic collective noun deriving from the Semitic root jnn , whose primary meaning is “to hide”. Some authors interpret the word to mean, literally, “beings that are concealed from the senses”. Such creatures are believed to inhabit desolate, dingy, dark places where they are feared. Jinn exist invisibly amongst humans, only detectable with the sixth sense. The jinn are subtile creatures created from smokeless fire (fire and air) thought to be able to possess animate and inanimate objects. Unlike demons, they are not necessarily evil, but own a capacity of free-will.

Possession is not caused by Satan, who is said to be just a tempter, whispering evil suggestions into humans heart, but, even though not mentioned in canonical scriptures, according to folklore by jinn, who can enter a human body physically or haunting them mentally.
A possession by a jinn can happen for various reasons. 
Ibn Taymiyyah explained a Jinn could sometimes haunt an individual, because the person could (even unintentionally) harm the jinn; urinating or throwing hot water on it, or even killing a related jinn without even realizing it. In this case the jinn will try to take revenge on the person. Another cause for jinn possession is when a jinn falls in love with a human and thereupon the jinn possesses the human. Some women have told of their experiences with jinn possession; where the jinn tried to have sexual intercourse from inside their bodies.
Thirdly, it occurs when a jinn is evil and simply wants to harm a human for no specific reason, it will possess that person, if it gets the opportunity, while the human is in a very emotional state or unconsciousness.

Recited formulas, referred to as Ruqyah are used to expel the Jinn from the body.

In a typical Islamic exorcism the treated person lies down while a white-gloved therapist places a hand on their head while reciting verses from the Quran.

Specific verses from the Quran are recited, which glorify God and invoke his help. In some cases the adhan (call for daily prayers) is also read, believed to have the effect of repelling non-angelic unseen beings or the jinn.

The Islamic prophet Muhammad taught his followers to read the last three suras from the Quran, Surat al-Ikhlas (The Fidelity), Surat al-Falaq (The Dawn) and Surat an-Nas (Mankind).