Detailed medical history and careful physical examination to understand the pathogenic factors, pathogenesis pattern and disease characteristics, and to diagnose peripheral vascular diseases from clinical symptoms and signs are the most important clinical diagnosis methods that should not be neglected. Clinically, the diagnosis of peripheral vascular disease should focus on understanding the following points. I. Limb temperature and color changes Cold and chilly limbs, reduced skin temperature, loss of proper cold tolerance, pallor, flushing, cyanosis, which are chronic limb artery occlusive diseases – thrombo-occlusive vasculitis, occlusive atherosclerosis, aortitis, diabetic vasculopathy, etc., occurring limb artery stenosis or occlusion and The disease is caused by blood circulation disorders. Raynaud’s syndrome is characterized by intermittent episodes of symmetrical pale – cyanotic – flushed skin color changes in both hands (upper extremities first and lower extremities later), accompanied by coldness, coldness and pain in the fingers or toes, and the symptoms disappear after the episode and return to normal. In case of cold, the coldness and coldness of the extremities are aggravated, cold and pale, indicating insufficient blood supply to the arteries of the extremities and very low blood flow. Cold and cold extremities, persistent cyanosis or petechiae and petechiae at the extremities, and altered skin and toe (finger) nail dystrophy are signs of severe limb ischemia. Second, limb pain Thrombo-occlusive vasculitis is overwhelmingly in young and middle-aged men (under 40 years of age), the onset is mostly unilateral lower limb, and later gradually involves other limbs (lower limb first and then upper limb onset), with distension, numbness or spasmodic pain, and very intense resting pain. Occlusive atherosclerosis mostly occurs in middle-aged and elderly people (age above 40 years), as a local manifestation of systemic atherosclerosis in the limbs, mostly with the onset of extremities, both lower limbs are heavy, with numbness and distension, and the pain is generally mild and tolerable. Atherosclerosis occurs mostly in adolescent females and is mainly characterized by limb weakness, coldness and fear of cold, and very mild swelling and pain. In contrast, erythematous limb pain is a paroxysmal burning severe pain in both feet or both hands, with red, burning skin and increased skin temperature. Clinically, chronic arterial occlusive disease of the limbs, patients with fixed persistent severe pain in the toes (fingers) and feet is often a precursor to the occurrence of ulceration, which should be noted and actively treated with a combination of Chinese and Western medicine. The sudden occurrence of severe pain in the limbs should be considered in two aspects: 1, accompanied by cold extremities, pale and purple skin, loss of sensation and impaired movement, then it is acute limb artery embolism or acute limb artery thrombosis. 2. Acute lower limb deep vein thrombosis if accompanied by extensive swelling of the limb, superficial vein and capillary dilation. Third, intermittent claudication Chronic lower limb arterial occlusive disease, 70% of patients often have intermittent claudication as its main manifestation, or intermittent claudication as the first appearance of symptoms, indicating the existence of ischemia and blood circulation disorders in the lower limbs. Therefore, understanding intermittent claudication is important for clinical diagnosis, judging the degree of ischemia of the limb, and determining the efficacy of treatment. Intermittent claudication manifests: when the patient walks a certain distance, distension, soreness or throbbing pain occurs in the calf (gastrocnemius) and palm of the foot, and is forced to pause slightly or rest for 2~5 minutes, the symptoms quickly relieve and disappear, and the same symptoms still appear if the affected limb is walked again. The shorter the intermittent claudication time and distance, the more serious the ischemia of the affected limb. Severe lower limb ischemia, the limb is obviously cold, cold, pale or cyanotic, there are changes in nutritional disorders, then the pain of intermittent claudication is aggravated, and the patient can only walk 50~l00 meters. Clinically, attention should be paid to other lower limb pain disorders (non-ischemic diseases) to differentiate from intermittent claudication. IV. Limb swelling Limb swelling is mainly caused by lower limb venous blood return disorder, lower limb venous blood backflow and lymphatic return disorder. Sudden widespread swelling of the whole lower limb (mostly in the left lower limb), along with swelling and cramping pain in the iliolumbar region and femoral triangle, is iliofemoral vein thrombosis. When the thrombus develops upward and extends to both lower extremities with obvious swelling, or when the swelling of both lower extremities occurs successively, inferior vena cava obstruction or iliofemoral vein thrombosis on both sides should be considered. If the lower leg is obviously swollen, distended and painful with pressure, it is deep vein thrombosis of the lower leg or thrombosis of the muscular plexus of the lower leg. If the diagnosis and treatment are delayed, the thrombus will continue to extend from the calf to the thigh and iliofemoral vein thrombosis will occur. It should be especially noted that acute lower limb deep vein thrombosis can cause arterial spasm of the limb, femoral cyanosis, severe limb swelling, severe swelling and pain, cyanosis, chilling, weakening or disappearance of arterial pulsation of the affected limb, and gangrene of the limb can occur. According to the scope and degree of swelling of the limb, the site of deep vein thrombosis of the lower limb can be judged. Superficial varicose veins of lower limbs with limb swelling, or simple limb swelling with lower limb fatigue when walking should be considered as lower limb deep vein valve insufficiency. Longer course of lower extremity deep vein thrombosis and lower extremity deep vein valve insufficiency can be complicated by lymphedema at the same time due to the involvement of lymphatic system. Lower extremity dengue, often caused by lower extremity venous stasis, tinea pedis and lower extremity infection. It starts with generalized chills, high fever, large patches of erythema on the feet and lower legs, redness and swelling, burning pain, and can spread rapidly to the surrounding area. Due to repeated attacks, the lymphatic vessels of the lower extremities are involved and obstruction occurs, causing lymphedema and finally the formation of elephantiasis. Difficulties in clinical diagnosis should be performed with lower limb venography, ultrasound Doppler examination, CT angiography, etc. for clear diagnosis. V. Superficial varicose veins of lower extremities Superficial varicose veins of lower extremities are the most common clinical manifestations of many lower extremity venous diseases: 1. Venous backflow diseases of lower extremities: lower extremity deep vein valve insufficiency, simple lower extremity varicose veins, lower extremity deep vein thrombosis syndrome (recanalization phase), etc.; 2. Venous backflow disorders of lower extremities: lower extremity deep vein thrombosis (occlusion phase), lower vena cava obstruction, Bu-ga syndrome, lower limb venous malformation-bone hypertrophy syndrome (Klippel-Treaunay disease), iliofemoral vein compression syndrome, etc. Clinically, these lower extremity venous disorders should be thought of for diagnosis and differential diagnosis in patients with superficial varicose veins of the lower extremities. Simple lower extremity varicose veins: superficial varicose veins in the anterior medial aspect of the lower extremity, which travel upward to the medial femoral aspect and merge with the femoral vein at the oval fossa, are saphenous varicose veins; superficial varicose veins in the posterior lateral aspect of the lower leg, which travel upward into the N vein, are small saphenous varicose veins. Simple saphenous vein and small saphenous varicose vein can be completely asymptomatic or only have a feeling of heaviness and fatigue in the lower limbs, etc. There is usually no swelling of the lower limbs. If the varicose veins of the lower extremities are more obvious or accompanied by swelling of the lower extremities, most of them also have lower extremity deep vein valve insufficiency or lower extremity deep vein thrombosis. Superficial varicose veins of both lower extremities with swollen limbs, along with dilated and varicose superficial veins in the pubic area, lower abdomen and hip should be considered as inferior vena cava obstruction or iliofemoral vein thrombosis on both sides. Widespread dilatation and varicosity of superficial veins throughout the lower extremities, scattered elevated varicose venous tumors are seen, and the affected limb grows thicker than the healthy limb, which may be congenital trabecular hemangioma or congenital arteriovenous fistula. Sixth, wandering thrombotic superficial phlebitis thrombo-occlusive vasculitis, often involving limb arteries and veins, 30% to 60% of patients have recurrent episodes of wandering thrombotic superficial phlebitis in the limb, with painful red nodules, plaques and cords on the skin, burning, and pressure pain. In some patients, the onset of the disease first invades the veins of the limb with episodes of wandering superficial thrombophlebitis, often intermittently and repeatedly for months, years or 10 years before involving the arteries of the limb and showing signs of limb ischemia. This is a feature of diagnostic significance. Any young and strong male with a long-term smoking habit who has repeated episodes of wandering thrombotic superficial phlebitis in the limb before the appearance of limb ischemic symptoms should also consider thrombo-occlusive vasculitis and actively treat it to control the disease development. VII. Limb ulceration and gangrene After arterial occlusion or embolism of the limb, ulceration or gangrene often occurs due to severe blood circulation disorders in the limb. Attention should be paid to the cause, time, location, and extent of ulceration and gangrene, the condition of the wound, and whether the boundary of gangrene is clear. Ulceration and gangrene in thrombo-occlusive vasculitis (mainly involving the middle and small limb arteries) often starts at the toe end (bunion or little toe) and slowly progresses to the back of the foot, showing dry gangrene, mostly confined to the foot. Occlusive atherosclerosis (mostly involving the large and medium limb arteries) gangrene begins in the foot and progresses more rapidly, involving the lower leg, femur, and even the ilium or perineum, with dry gangrene. Diabetic gangrene develops rapidly and can spread to the foot and lower leg, mostly as wet gangrene. Raynaud’s sign (mainly involving the small finger and toe arteries) occurs only at the end of the finger (toe) with a small, limited, superficially present skin ulcer, and extension is exceptionally rare. Acute limb artery embolism and acute limb artery thrombosis have an acute onset and widespread gangrene involving the foot, lower leg, and femur. Venous stasis ulcers of the lower extremities are mostly caused by venous hypertension, stasis, and hypoxia due to lower extremity deep vein valve insufficiency and lower extremity deep vein thrombosis. Their clinical features: chronic stasis ulcers have specific sites, often occurring in the lower 1/3 of the inner and outer calf (pollicization), accompanied by skin pigmentation and stasis dermatitis. In addition, congenital arteriovenous fistulas and trapezoid hemangiomas of the lower extremities can also occur with limb ulcers and gangrene. Chronic arterial occlusive disease can cause vascular murmurs due to vortex flow when the artery is narrowed. During clinical examination, attention should be paid to vascular murmurs in the affected arterial sites, such as the neck, supraclavicular fossa, chest, abdomen, back, lumbar region and inguinal region. This is of great value in diagnosing and judging the condition. Aortitis should be considered in any adolescent (under the age of 30) female with ischemic symptoms in the limbs, diminished or absent arterial pulsations, and a vascular murmur on auscultation. In middle-aged and elderly (age 40 years or older) patients, where there are symptoms of ischemia in the limbs, diminished or absent arterial pulsations, and a vascular murmur is heard at the site of the lesion, it may be occlusive atherosclerosis. In arteriovenous fistulas of the limb, tremor can be felt locally and a continuous vascular murmur can be heard on auscultation. In limb aneurysms, a pulsating mass with tremor may be palpated and a systolic vascular murmur may be auscultated. For arterial occlusive and embolic diseases, correct palpation of the arterial pulsation of the extremities can determine the presence or absence of arterial occlusion and more accurately determine the degree, extent and plane of arterial obstruction, which is important for the diagnosis of peripheral vascular diseases. In thrombo-occlusive vasculitis, occlusive atherosclerosis, diabetic vasculopathy, and aortitis, there are symptoms of ischemia in the limbs, and at the same time the arterial pulsations in the limbs are weakened or absent. Acute limb arterial embolism and acute arterial thrombosis with acute ischemic symptoms in the limb and loss of arterial pulsation below the plane of embolism. Patients with aortitis (pulselessness) often present with pulselessness of the upper extremities, and on examination, they are found to have absent radial, brachial, and axillary arterial pulsations and undetectable blood pressure, and angiography confirms occlusion of the subclavian artery. In occlusive atherosclerosis and thrombo-occlusive vasculitis, when the upper extremity is involved, the arterial pulsations of the upper extremity disappear and symptoms of ischemia appear, but the diagnosis of pulselessness should not be made and should be differentiated from aortitis. The anatomical abnormality of the dorsalis pedis artery must also be taken into account: about 5% to 13% of normal people have absent dorsalis pedis arteries without being able to palpate them, but there are no signs of ischemia. Therefore, a comprehensive clinical analysis must be performed based on symptoms and signs, and the diagnosis of arterial occlusive disease of the limb cannot be made simply by the disappearance of arterial pulsations in the limb. Ten, tongue and pulse Clinical observation of changes in the tongue and pulse is of great value for guiding the development and prognosis of peripheral vascular disease, as well as for guiding clinical diagnosis and treatment. Mild gangrenous infection of the limb and acute deep vein thrombosis of the lower extremity may present with yellow moss and red-red tongue, which is evidence of stasis-heat, and it is appropriate to use the method of clearing heat and activating blood. Severe gangrene of the limb with secondary infection and high fever may present with yellow mantle and red-red-vivid tongue or mangosteen, which is evidence of heat toxicity and heat injures yin. Ischemia of the limbs or stasis in the deep veins of the lower limbs, with white moss and red-red-vivid tongue or petechiae, is a sign of blood stasis, and it is advisable to invigorate the blood and remove stasis. A sunken, thin and weak pulse is a sign of stasis of Qi and Blood, mostly seen in aortitis, etc. Slippery, thin and astringent pulse is evidence of phlegm stasis, mostly seen in occlusive atherosclerosis, etc. When diagnosing the pulse in the upper extremity, we should also pay attention to the anatomical abnormalities of the radial artery: when there is no pulse in the inch opening alone, there may be a “reverse guan pulse” or an “oblique flying pulse” behind the wrist.