Diagnostic Essentials for Thromboangiitis Obliterans in Chinese medicine:
(1)  It is often seen in the males at the age of 20-40, with a history of invasion of cold and dampness, longterm cigarette smoking, and traumatic injury.
(2)  It often occurs in the cold season, with one side of the limb involved first, the other side of the limb involved progressively and the upper limb involved in a few cases. In accordance with the clinical manifestations, it can be divided into three phases.

Phase I (Local Ischemia): It is manifested by cold sensation, chills, soreness and pain and numbness in the last segment of the infected limb. After walking about 500-1000 meter, the sole feels stiff immediately and claudicafion appears due to sore and distending sensation in the calf. After rest for 3-5 minutes, the stiff, sore and distending sensation can be relieved. If walking for a same distance, the above-mentioned symptoms (intermittent claudication) can occur again. Slight muscular atrophy, dry skin,decreased perspiration and slow growth of the nails canhappen in the infected foot. The artery in the dorsum of foot can be decreased.

Phase II (Dystrophy): Cold sensation, chills, sore, painful and numb sensation, and intermittent claudication can be gradually aggravated. Pain can appear at night to cause insomnia. There are obvious muscular atrophy, dry skin, desquamation, exfoliation of digital hair, no sweating in foot, thickened and deformed toenails, slow growth of toenails, pale skin or slightly red skin or purple red skin, no pulsation in the dorsal artery of the foot.

Phase III (Necrosis): Swelling and purple color occur in the toes, and ulceration or gangrene can also possibly occur. Purple dark and dry toes can also possibly happen to cause dry gangrene. Ulceration and gangrene can be gradually enlarged and accompanied by serious pain.

(3) Doppler ultrasonic examination, tachogram, nail fold microcirculation, and arteriography can be used for auxiliary diagnosis and evaluation of the condition. The total count of peripheral leukocyte and neutrophil ratio can be obviously enhanced in the necrosis stage.