The first includes pathophysiological conditions in which a Primary blood abnormality causes a decrease of blood flow, as occurs In polycythaemic vera, sclerocythaemic and seric hyperviscosity Syndromes, and may be referred to as primary blood hyperviscosity Syndromes’. The second group includes pathological conditions in which a primary reduction of blood supply to tissure provokes tissue ischaemia, and an impairment of rheological properties of blood can be observed at microcirculatory level. Thus, these situations have been described as ‘secondary blood hypervi- scosity syndromes’ patients with peripheral obliterative arterial disease, ischaemic cardiophthies and cerebrovascular insufficiencies show a diminution in blood fluidity during spontaneous or provoked ischaemic conditions which disappears after reperfusion of the tissue. The pathogenesis of this rheological damage is unclear, but may arise from the complex relationship among blood ceel(red cells, leucocytes, platelets), endothelium and plasma components. In addition to these 2 groups of blood hyperviscosity syndromes,several pathological states such as diabetes, shock surgery, and rheumatic disease have been described in which an increase of blood viscosity can be observed. For these situations, which require much further investigation, the term’ syndromes associated with blood hypervi- scosity’ could be proposed.

Blood hyperviscosity may cause a variety of clinical Manifestations including bleeding from mucosal membranes, Congestive heart failure, retinopathy, and various neurologic deficits, But it might be treated with ILILT. Nie et al.(2005) has treated 100 Patients with hyperviscosity with LGal at 5mW for 30 min each Time, which was done two times each day for five days and found the blood viscosity, plasma viscosity, fibrinogen, erythrocyte aggregation index, erythrocyte deformability index and erythrocyte sedimentation rate decreased, respectively. Blood cells flowing in nasal mucosa might mediate ILILT induced viscosity decrease.

Blood hyperviscosity might be also treated with laser Acupuncture and the skin-contact electric acupuncture of low frequency pulse. The patients with brain contusion were irradiated with LGAL at 10-15mW on futu acupoint (LI18) (Fig.7) of both side for 30 min (cheng et al.2000). it has been found that low cut blood viscosity and hematocrit significantly decrease.