Red blood cells production: 

Dear noble brothers, you all know that red blood cells production is done in bone marrow. 

These are the most important laboratories ones in the human body, as they produce two and a half million red blood cells every second. 

There is a stubborn disease called leukemia,

which is known as anemia as well, and it causes red blood cells production to stop. Actually, this disease is fatal, and up till now, no cure has been discovered for it. However, some scientists have discovered that there are organs in the body that monitor blood volume. 

Blood is the most critical thing in human body, and if its amount decreases, these monitoring organs send signals to the laboratories of red blood cell to increase their activity. This discovery has highlighted the wisdom of Hijamah (cupping). The Prophet, peace be upon him, said: 

(The best medicines you may treat yourselves with are Hijamah and sea incense.)

[Al-Bukhari- on the authority of Anas]

If you want to have Hijamah, the best time is the 17th, 19th of 21st of the lunar month. Don’t let the blood volume increase in the body as it might be deadly.

What happens if the blood volume increases? When the blood volume increases in the vessels the heart gets tired, and Hijamah is what decreases it. In fact, decreasing this volume of blood urges the laboratories of red blood cells to produce more cells, and this is the way they are maintained.

Thus, red blood cells production is maintained by decreasing the volume of blood in one way or another (in order to reactivate it again).       
The blood volume increase causes high blood pressure, which is considered the silent killer

as it has no symptoms. Man suddenly discovers that his blood goes to 150 or 220, for instance, after measuring it. 

“Do Hijama lest and do not let your blood become hyperemic (becomes excessive) lest it kills you.” 

[Al- Bazzar and Ibu An’eem from Ibn Abbas] 

When the blood becomes hyperemic it means that its volume becomes excessive and it causes high blood pressure, or the arterial hypertension, which is called the silent killer. In some cases, the high blood pressure causes paralysis, loss of sight and other health problems that only Allah knows. 

The main cause of high blood pressure is stress, as man's psychological condition affects his blood pressure. 

(I have never heard anyone who came to the Prophet, peace be upon him, having headache, but he said to him, "Have Hijamah done to you.")

[Tahtheeb Al-Athar by At-Tabari, on the authority of Ayub bin Hasan]

A woman went to a European country to be treated from migraine.

The doctor asked her, "Are you Muslim?" She replied, "Yes, I am." Then he said, "Have Hijamah done to you." This remedy is amazing! 

There is an expetion for women regarding Hujamah; as women do not need Hijamah as long as they are having their period, because the increased volume of her blood gets out of her body during her period. However, after menopause, women need to have Hijamah done to them just as men do.   

Benefits of Hijamah:

Dear brothers, there are many Ahadeeth about Hijamah as a remedy for many illnesses, such as migraine and arterial hypertension. Also, Hijamah is prescribed when red blood cell production stops producing red blood cells, which is a fatal disease. 

Hijamah is an act of Sunnah, so I would like to refer to the fact that the instructions of the Prophet, peace be upon him, concerning health have nothing to do with the culture of his time, his personal opinion or his experience, nor the environmental facts. Those health instructions of the Prophet, peace be upon him, are an inspiration inspired to him as Allah the Almighty says:   

(Nor does he speak of (his own) desire* It is only an Inspiration that is inspired.)

[An-Najm, 3-4]

A western scientist, who never knows that there is Hijamah in Islam, said, "Losing some amount of blood regularly protects man from heart attacks."