Pathology: Blood or qi deficiency. This is seen in cases of deficiencies and failure of Qi and blood. It can also be seen in disharmonies of the even emotions, weakness in Yang Qi, internal damage to jing, and penetration of dampness.
Testing for venous blood clots. Venous blood clots may be detected in a variety of ways, though ultrasound is most commonly used. Occasionally, the patient's size and shape limit the ability for ultrasound to provide a definitive answer. Venography is an alternative test to look for a clot.
1 A dye (contrast agent) is injected into a large vein in your foot or ankle. An X-ray procedure creates an image of the veins in your legs and feet, to look for clots. However, less invasive methods of diagnosis, such as ultrasound, can usually confirm the diagnosis.  CT or MRI scans.