Cupping in Islam: Virtues and Benefits
Question

What is hijamah (cupping) and how do you perform it?
Praise be to Allah.Linguistic meaning of cupping 
The word hijamah (cupping) comes from the word hajm which means sucking, as in the phrase hajama al-sabiy thadya ummihi (the infant suckled his mother’s breast). 
Al-Hajjam means the cupper, hijamah is the profession of cupping, and the word mihjam is used to describe the vessel in which the blood is collected and the lancet used by the cupper. (See Lisan al-‘Arab). 
Technical meaning of cupping
In fiqh terminology the word hijamah is applied by some scholars to the extraction of blood from the nape of the neck by means of cupping after making an incision with the lancet. Al-Zarqani stated that cupping is not limited to the nape of the neck, rather it may be done on any part of the body . This was also the view of al-Khattabi. 
In conclusion, hijamah refers to the extraction of blood from the body by means of cupping using a suitable vessel or whatever modern equipment that serves the same purpose. 
History of cupping
Cupping has been known since ancient times. It was known to the Chinese, the Babylonians and the Pharaohs. Their relics and carved images indicate that they used cupping to treat some diseases. At first they used metal cups or bulls’ horns, from which they would remove the air by sucking it out after placing the cup on the skin. Then they used glass cups from which they would remove the air by burning a piece of cotton or wool inside the cup. 
Virtues of cupping:
Al-Bukhari narrated in his Sahih (5269) from Sa’id ibn Jubayr from Ibn 'Abbas (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “Healing is in three things: drinking honey, the incision of a cupper, and cauterizing with fire, but I forbid my ummah to use cauterizing.” 
Al-Bukhari (5263) and Muslim (2952) narrated that Anas ibn Malik was asked about the earnings of the cupper, and he said: The Messenger of Allah (peace and blessings of Allah be upon him) was treated with cupping by Abu Taybah. He ordered that he should be given two sa’ of food, and he spoke with his masters so that they reduced what they used to take from his earnings. And he said: “The best medicine with which you treat yourselves is cupping, or it is one of the best of your medicines.” 
Jabir ibn ‘Abd-Allah (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: “If there is anything good in the medicines with which you treat yourselves, it is in the incision of the cupper, or a drink of honey or cauterization with fire, but I do not like to be cauterized.” (Narrated by al-Bukhari, 6583; Muslim, 2205). 
Benefits of cupping:
Cupping has real benefits in treating many diseases, past and present. The diseases which have been treated by cupping and for which it has been of benefit by Allah’s Leave include the following: 

Circulatory diseases
Treating blood pressure and infection of the heart muscle
Diseases of the chest and trachea
Headache and pains in the eyes
Pain in the neck and stomach, and rheumatic pain in the muscles
Some diseases of the heart and chest, and pain in the joints

In addition, cupping may offer a unique treatment which may reduce pain, and it does not have any side-effects. For more information on the benefits of cupping, please see Zad al-Ma’ad by Ibn al-Qayyim, 4/52, and al-Hijamah: Ahkamuha wa Fawaiduha by Ibrahim al-Hazimi.  
How cupping is done
The mouth of the cupping vessel (nowadays they use glass vessels) is placed on the skin at the site chosen for cupping. Then the cupper rarefies the air inside the vessel by burning a small piece of paper or cotton inside the vessel, so that the mouth of the vessel will cling to the skin. Sometimes a machine is used instead of the method described above. The vessel clings to the skin and is left for a period of three to ten minutes. Then it is lifted off and a very small incision is made in the skin using a clean sharp instrument such as a razor blade or the like. Then the cup is put back in the same manner as described above, until it is filled with the bad blood that comes out of the veins. Then it is taken off, and may be put back once more if needed. When it is finished and the cup is taken away, a dry dressing is placed over the site of the incision. (See Mabahith fi’l-Jarahah al-Sughra wa’l-Takhdir by Prof. Dr. Nazmi al-Qabbani). 
Before ending we should point out that no one should undertake cupping except one who can do it well, because of the harm that may result if it is done by one who is incompetent. 
For more, please see these answers: 12610 , 14325 , 128170 and 60162 .
And Allah knows best.