A. Medical history Detailed medical history is extremely important for the diagnosis and differential diagnosis of peripheral vascular disease. Pay attention to the onset, limb pain, skin color and temperature, limb dystrophy, ulcers and gangrene, etc., and understand the evolution, pattern and characteristics of the disease, as well as past history. The vast majority of thrombo-occlusive vasculitis are young and strong (20-40 years old) men, and women are rare. If a female patient complains of cold limbs, weakness and pain, Raynaud’s syndrome, aortitis and other diseases should be considered first. If thrombo-occlusive vasculitis is considered first, an incorrect diagnosis is often formed. The limb pain in chronic arterial occlusive disease of the limbs is mainly in the toes (fingers) and calves, and the pain of intermittent claudication of the lower limbs is mainly in the foot and plantar area and calves, and it is very rare to see pain in the thighs alone. If the pain in the thigh occurs first alone, it is generally not an arterial occlusive disease of the limb, and other diseases should be considered. Knowing the distance and duration of intermittent claudication of the lower extremities is valuable in determining the degree of lower extremity ischemia and can be used as a criterion for determining the effectiveness of treatment. In 70% of patients with chronic arterial occlusive disease of the limbs, intermittent claudication is often the main manifestation or the first symptom: when walking for a certain distance, there is distension, soreness, throbbing and stiffness in the calf and foot, which can be relieved or disappeared after a slight rest for 2-5 minutes. Bone and joint disease occurs when the patient starts walking and the pain is aggravated when walking and standing for too long or walking with weight, and the pain persists after 10 minutes of rest. This point, can be distinguished from intermittent claudication. Chronic arterial occlusive disease of the extremities, with manifestations of limb ischemia, is often limb heavy. If resting pain is severe, fixed persistent severe pain in the toes (fingers) and feet is often a precursor to ulceration and should be noted. Early or during the onset of thrombo-occlusive vasculitis, 30-60% of patients have recurrent episodes of wandering superficial thrombophlebitis in the limb, which is a diagnostic feature. Raynaud’s syndrome (syndrome) is manifested by intermittent episodes of symmetrical pale, cyanotic, and flushed skin color changes in both hands in three stages, accompanied by cold and painful fingers, and after the episode all symptoms disappear and return to normal. This is the vasospastic phase (early stage). If the disease develops, it can involve both lower extremities and face, and enter the stage of dystrophy, with persistent coldness, coldness, numbness and pain in both hands and feet, dry and flaky finger skin, dry and shrunken soft tissues, persistent pallor or cyanosis, which cannot make the ischemic manifestation completely subside even in the warm summer. At this point, organic changes in the small arteries of the fingers (toes) and arterial occlusion occur. Finally, in the ulcerative stage, the nutritional disorder of the extremity is aggravated, and limited superficial skin ulceration or necrosis of the finger (toe) end occurs, or even nail loss, shortening and drying of the finger. Treatment is most effective during the vasospastic phase, and when the artery is completely occluded, treatment is difficult to completely eliminate ischemic symptoms in the hands and feet. Tracing the onset of the trigger can help in the diagnosis of the disease. Deep vein thrombosis of the lower extremities is prone to occur after surgery, trauma, prolonged bed rest for women after childbirth, infection of the lower extremities and malignant tumors. The site of pain in the limb of lower extremity deep vein thrombosis is related to the site of thrombus obstruction. If the onset of the disease is rapid, with sudden and obvious distension and pressure pain in the inguinal region (femoral triangle), followed by widespread swelling of the lower limbs, then it is iliofemoral vein thrombosis. If the pain and swelling in the calf are obvious, then it is N vein thrombosis. In contrast, the onset of calf muscle plexus thrombosis is mostly insidious, with only mild swelling and pain, and is often overlooked. Occlusive arteriosclerosis is a common chronic arterial occlusive disease of the limbs in middle and old age, which is a local manifestation of systemic atherosclerosis in the limbs. In recent years, with the continuous improvement of people’s life and the change of diet structure in China, eating too much meat and animal fat, this disease is increasing, and the age of onset is early, and clinically it is common to see patients around 40 years old with obvious manifestations of limb ischemia, which should be taken seriously. The lesions mainly involve the large and middle arteries, most commonly the aorta, common iliac artery, femoral artery, N artery, etc. The onset of the disease in all four limbs, with the lower limbs in a more severe condition and the upper limbs in a light condition, is in a stable state in the early stage of the disease, and the limb ischemia manifestations are not obvious and often ignored by patients. Thereafter, coldness, coldness, numbness, pain, intermittent claudication, persistent pale, purplish or cyanotic skin, and gradually aggravated changes in the nutritional disorders of the limbs gradually appear. At the same time, it is often complicated by hypertension, coronary heart disease, diabetes mellitus and cerebrovascular disease. These clinical features are important for a clear diagnosis of this disease, which is obviously different from thrombo-occlusive vasculitis. The physical examination of the limbs mainly includes: skin color and temperature, changes in nutritional disorders, sweat hair, toe (finger) nail growth, muscle condition, erythema nodosum, limb swelling, varicose veins, ulcers and gangrene, arterial pulsation, etc., as well as tongue coating and pulse. Skin color and temperature Observation of skin color and temperature can estimate the condition of blood circulation in the limb. Altered nutritional disorders Chronic arterial occlusive disease of the limb results in dry, thin, flaky skin and even petechiae and ecchymosis at the extremities due to limb ischemia and stasis of blood. Wrinkling of the hands and feet occurs due to absorption of subcutaneous tissue. Sweat hair and toe (finger) nail growth condition Due to impaired blood circulation in the limbs, sweat hair is lost on the feet and lower legs; toe (finger) nail growth is slow, toe (finger) nails are dry and thick, deformed, depressed, or ingrown nail-like growth, and nail fungus easily occurs, which causes ulceration or gangrene. Muscle condition Chronic limb arterial occlusive disease, due to limb ischemia and reduced activity after the disease, the affected limbs have different degrees of muscle atrophy, and the most common is the calf muscle atrophy is obvious. When the calf muscles are extremely atrophied (the skin is attached to the bone), it is difficult to improve blood circulation in the foot, and amputation is usually required if gangrene infection of the foot occurs. Erythema nodosum Early or during the course of thrombo-occlusive vasculitis, recurrent episodes of wandering superficial thrombophlebitis in the foot and lower leg, with reddened nodules, plaques and cords on the skin, burning and pressure pain. Care should be taken to differentiate it from nodular vasculitis, erythema nodosum, sclerosing erythema, and lipofuscinosis. Limb swelling The extent of limb swelling in lower extremity deep vein thrombosis is related to the site of thrombosis. In iliofemoral vein thrombosis, there is widespread swelling and coarse swelling of the entire lower extremity with significant distension and tenderness. in N vein thrombosis, there is swelling of the ankle and lower calf with fullness and tightness and tenderness. Calf muscle plexus thrombosis with swelling and tenderness in the calf belly. Extensive and marked swelling of both lower extremities, swelling of the lower back and lower abdominal wall, and the presence of dilated superficial veins in the lower abdominal wall and perineum should be considered as iliofemoral vein thrombosis or inferior vena cava obstruction on both sides. Either thrombosis of the muscular plexus of the lower leg, with upward extension and expansion of the thrombus, or primary iliofemoral vein thrombosis, with downward extension and expansion of the thrombus, can involve the entire deep venous system of the lower extremities, which is more common in clinical practice. If not treated early (within 7 days of onset), the lower extremity deep vein valves will be destroyed and the vein wall will be damaged, which often leaves the lower extremity venous insufficiency and leaves the limb in a diseased state, making treatment very difficult. Acute iliofemoral vein thrombosis, if accompanied by arterial spasm of the limb, severe pain in the affected limb, severe swelling, extensive cyanosis, skin blistering, cold limb, loss of arterial pulsation, called femoral cyanosis, and even venous gangrene. Diseases such as varicose veins of the lower extremities and deep venous insufficiency of the lower extremities also often have swollen limbs. Clinically, we see patients with swollen calves and fatigue when walking without varicose veins, and color ultrasound Doppler examination, which confirms lower extremity deep vein valve insufficiency. Lower extremity deep vein thrombosis and lower extremity varicose veins can occur due to venous reflux obstruction or blood backflow and prolonged stasis in the lower extremity, which can involve the lymphatic vessels and can lead to lymphedema. Varicose veins of the limbs Varicose veins of the lower limbs are common clinical manifestations of many lower limb venous diseases: primary lower limb deep vein valve insufficiency, lower limb deep vein thrombosis, inferior vena cava obstruction, Bou-ga syndrome, iliac vein compression syndrome, lower limb venous malformation bone hypertrophy syndrome, congenital venous valveless disease, etc., can be secondary to varicose veins of the lower limbs. Therefore, it is important to make an etiologic diagnosis of varicose veins in the lower extremities. The lower extremities should be fully exposed, both anterior and posterior to the lower extremities should be examined for saphenous and small saphenous venous lesions, and attention should be paid to the communicating veins. Ulceration and gangrene Chronic arterial occlusive disease of the limb often results in ulceration or gangrene of the extremity due to severe limb ischemia, which may extend to the dorsal aspect of the foot and ankle, mostly dry gangrene. Diabetic gangrene is wet gangrene with heavy secondary infection. If there are ulcers and gangrene at the toe end or palm of the foot with good arterial pulsation in the limb and no ischemic manifestations, congenital malformations of the spine, spinal cord disease, etc. should be considered. Varicose veins of lower extremities and deep vein thrombosis of lower extremities, in the later stage, due to the destruction of deep vein valves and traffic branch vein valves, hypertension of lower extremity veins, stasis and hypoxia, skin dystrophic changes occur, skin and subcutaneous tissue fibrous sclerosis, skin pigmentation, brownish color. In case of minor trauma, stasis ulcers of the lower extremities are prone to occur, often with specific sites on the lower 1/3 medial and lateral calf (ankle area, at the traffic branch veins). Arterial pulsation In chronic arterial occlusive disease of the limbs, palpation of the arterial pulsation of the limbs is an important step in the limb examination to determine the presence or absence of arterial occlusion, and the degree, extent and plane of arterial obstruction can be determined more accurately. Weakened or absent limb artery pulsation is an important basis for the diagnosis of chronic occlusive limb artery disease. However, the anatomical abnormalities of the limb arteries must be taken into account. About 5% to 13% of normal people have absent dorsalis pedis artery and posterior tibial artery that cannot be felt, or have diminished pulsation, but the limb does not show ischemia, which cannot be treated as a disease. In the case of aortitis and occlusive arteriosclerosis, attention should also be paid to the presence of vascular murmurs in the neck, abdomen, and groin area. Pulselessness in the upper extremities is a clinical manifestation of aortitis. In the case of thrombo-occlusive vasculitis, occlusive arteriosclerosis and other diseases that invade the upper limbs, pulselessness can also occur, along with other limb ischemic manifestations, which cannot be diagnosed as “pulselessness” alone. Third, the auxiliary examination After taking the medical history and physical examination, if necessary and possible equipment, auxiliary examination can be performed to help the diagnosis, but must be combined with the clinical data analysis and comparison to have value. At present, clinical over-confidence in a certain instrument examination and neglect of detailed medical history and careful physical examination are the main reasons for clinical misdiagnosis and mistreatment. With the rapid development of modern science and technology, the application of some modern scientific examination instruments, the popularization of non-invasive vascular detection and angiography, etc. have important values for the early and localized diagnosis of peripheral vascular diseases. Such as ultrasonic Doppler vascular detection, photoelectric limb volume examination, X-ray examination, electronic computerized X-ray tomography, CT angiography, CNC subtraction angiography, as well as limb hemogram and microcirculation examination, etc., can be applied according to the condition of choice.