Hypertrichosis is a symptom of sympathetic chain syndrome. Skin irritation, such as increased sweating and hypertrichosis, may occur. Sympathetic chain syndrome is a long-standing, insidious clinical syndrome with multiple etiologies. Typical symptoms appear when ganglion damage is severe and compensatory capacity is weakened, and are often delayed and discovered incidentally at autopsy. The clinical manifestations vary depending on the damaged sympathetic ganglion, but all have common clinical symptoms. Such as pain, sensory impairment, vascular dysfunction, etc. The disease can occur at any age and can occur in both sexes. It is not rare clinically, and the clinical diagnosis rate is low because typical symptoms appear only in late stages. Mostly subacute or chronic onset, but also acute onset, usually with a tendency to turn into chronic and prolonged, on and off. The basic characteristics of local sympathetic chain lesions are: segmental asymmetry and strong diffusion and periodic exacerbation, etc. The clinical manifestations vary depending on the damaged sympathetic ganglion, but all have common clinical symptoms. Pain and sensory disorders Pain is episodic or persistent, with episodic exacerbation, heavier at night, mood swings, physical labor, weather changes and cold stimulation and other factors can make the pain worse, the scope is more diffuse, with a tendency to spread widely. The pain may be more diffuse and has a tendency to spread widely. Pressure pain may appear in the projection area of the damaged sympathetic ganglion, and the finding of pressure points often helps to localize the diagnosis. A variety of sensory abnormalities may appear, such as numbness, ant-like sensation, etc. Objective sensory disorders are less severe than subjective symptoms, mostly pain abnormalities, temperature abnormalities are less common, and tactile and deep sensory disorders are even less common. Skin and appendage changes The skin may show irritation symptoms, such as increased sweating and hyperactive hair reflex; it may also show symptoms of functional deficiency, such as reduced electrical conductivity of the skin, reduced sweating and weakened hair reflex. In addition, the skin can also appear nutritional disorders, dry atrophy, hair loss and brittle finger (toe) nails. 4, vascular dysfunction mainly manifested as small arteries and capillaries spasm, may also appear hypotonia, or even paralysis, as well as somatic nerve dysfunction.