Siravyadhana (blood letting ) is treatment for various diseases:

           Siravyadhana  explained by ancient Ayurveda can be co-related to Blood letting in modern era.Sushrutha the father of surgery had mentioned the siravyadhana as one of type of raktamokshana(panchakarma).In which the dushta(impure) blood is removed from the body parts to treat the disease.
            blood letting is done by selection of veins which runs above or below the affected area.so that it should not carry the same impure blood to other parts,by the needle or syringe the selected site is punctured and desired amount of blood is drawn.depending on the disease and its severity.

indications of siravyadhana:

                   the diseases caused due to rakta ie all blood related disorders are treated by siravyadhana.they are herpes, abscesses, splenomegally, indigestion,  fever, gingivitis, disease of eyes(redness, irritation), excess of thirst, Psoriasis, gout ,and also nasal bleeding.

sites of siravyadhana:

             siravyadha is done on the affected areas avoiding marma points(vital points mentioned in Ayurveda which when traumated will cause death  )nearby.the points of the siravyadhana are selected according to disease . here are some of the examples for few diseases.

In padadaha(burning feet),vatakantak(heel spur) -- 2 fingers above the kshipra marma (the space between 1st and 2nd  metatarsals) in feet.
In gout ,eczema,                          --2fingers above the kshipra marma (the space between 1st and 2nd metacarpels). in hands.

sciatica(gradhrasi)       --  4 fingers below or above the knee joints

goitre           --- the one at the base of the thighs.

cervical spondylosis -- the space between the two scapulae(shoulders).