Hijamah comes from the arabic root word "ha ja ma" which means "to diminish in volume", and refers to the reduction in blood volume or to the vacuum effect used to draw blood from the body. In the case of the ahaadeeth (sayings of the Prophet[SAW]) about hijamah it refers to the drawing of blood from the body for therapeutic purposes, either to support health in the case of one who is not sick or to cure a specific illness or ailment.
The vacuum or sucking effect can be achieved by many different methods including sucking with the mouth directly over a cut or wound (as in the case of poisonous bites), using a leech to draw blood, the use of instruments such as animal horns as was done in ancient times, or the more modern methods of using bamboo, glass or plastic "cups", either with fire or a pump mechanism.
The practice of applying a partial vacuum by these means causes the tissues beneath the cup to be drawn up and swell, thereby increasing blood flow to the affected area. This enhanced blood flow draws impurities and toxins away from the nearby tissues and organs towards the surface for elimination via the break in the skin layer created through the incisions made prior to the application of the "cup" or similar device.
Though Hijamah is commonly translated as "cupping" amongst english speakers, this is not an accurate translation because cupping in the modern sense can refer to both "dry" (where no blood is removed) and "wet" forms (which is Hijamah). Cupping is the practice of using cups, which can be of different materials, to create suction at the skin level in order to draw blood to the surface, which may then be removed in the case of "wet" cupping.
The earliest historical evidence of the use of Hijamah is from the ancient Egyptians. One of the oldest egyptian medical text books, written in approximately 1550 BC, describes "bleeding" used to 'remove pathogens from the body'. It is evident that bloodletting was considered a remedy for almost every type of disease as well as an important means of preserving good health and life.
Hippocrates and Galen were also great advocates of Hijamah. In Hippocrates' time bloodletting was topological and not used in terms of the theory of the 4 humors. Specific points were bled for specific illnesses. Galen explains that the principle indication for bloodletting is to eliminate residues or divert blood from one part of the body to another. His approach was based on two key Unani concepts prevalent at the time. First, that blood didn't circulate well in the body, and that it eventually went stagnant until it was "let out". Secondly, the concept of the balance of the four humors (blood, phlegm, black bile and yellow bile) was the source of health or illness, in which case bloodletting is used to bring about balance between these humors. Mapping out the blood vessels of the body, Galen would cut his patients in different areas, depending on what area he wanted to treat.
In the East, Bloodletting and wet cupping was always an integral part of the medical practices, and remains so to this day. The ancient Chinese medical text which is widely regarded as the oldest medical text in existence, the Nei Jing, or Inner Classic says that:
"if there is stagnation it must be first be resolved through bloodletting before the application of acupuncture or moxibustion."
By the mid to late 1800s however, bloodletting was sharply criticized by the medical fraternity and had fallen away as a popular method. Because of the procedure not being practiced correctly it was becoming responsible for a large number of deaths and therefore was increasingly being discredited by modern medicine, the newly established scientific model of medicine also began discrediting all other previously established traditional therapies in order to gain medical dominance.
In the past 20 to 30 years however, it has found a tremendous resurgence amongst Muslim communities, with courses being offered to both medical practitioners and the public in some countries like the UK.
There are many ahaadeeth that recommend the use of Hijamah such as this one:
Jabir bin Abdullah (RA) relates that he heard Rasulullah (SAW) saying: "If there is any good in your treatments it is in the blade of the Hajjaam, a drink of honey or branding by fire (cauterisation), whichever suits the ailment, and I do not like to be cauterized" (Bukhari & Muslim)
Hijamah though is a medical procedure that involves the handling of blood and body fluids and therefore while it has many benefits for general health and the treatment of illnesses, it must be performed by someone who has special training in Hijamah and the associated medical sciences in order to avoid adverse effects from the procedure.