Increased skin temperature is commonly associated with erythermalgia. Erythromelalgia is a disorder caused by excessive vasodilation of the extremities and is characterized by paroxysmal redness, increased skin temperature and burning pain in a warm environment. Primary cases are more common. It is a rare disease. Patients are mostly children or 40 years old. In the 433 cases reported in Guangzhou, young women accounted for 92.86% of the total number of cases, with a male to female ratio of 1/13. The onset of the disease is rapid, often causing or exacerbating attacks when the limb drops, stands or moves in a warm environment. Local skin temperatures above the critical temperature often cause attacks, and attacks are often more severe at night than during the day. The attack is characterized by symmetrical, paroxysmal, severe pain in both feet, mostly burning pain, occasionally stabbing pain or swelling pain. The skin is flushed and congested, and the skin temperature is increased with sweating. The dorsalis pedis and posterior tibial artery pulsations are increased. Cold compresses, elevation of the affected limb or exposing the foot to the outside of the bed, and local temperature below the critical temperature may relieve the attack and restore the skin color to normal. The pain is usually confined to the bunions and toes of the foot and, less commonly, to the corresponding areas of the hand. Each attack lasts for several minutes or even hours and is occasionally accompanied by local edema. Between attacks, the extremity is often left with mild numbness or pain, but is not accompanied by neurotrophic disorders such as ulceration or gangrene. The blood routine is the most general and basic blood test. Routine blood test is usually taken with peripheral blood examination, such as blood from the fingertip and earlobe area. After the blood cell analysis instrument, the computer reports the results, and this item has become a practice to examine patients. Blood consists of two major parts, liquid and tangible cells, and routine blood tests are performed on the cellular part of the blood. Blood has three different functions of cells – red blood cells (commonly known as red blood cells), white blood cells (commonly known as white blood cells), and platelets. Diseases are determined by observing changes in number and morphological distribution. It is one of the common auxiliary examinations for doctors to diagnose the condition. 2.Abdominal vascular ultrasound examination Abdominal vascular ultrasound examination of abdominal aortic aneurysm can measure the anterior-posterior diameter, long diameter and wide diameter of the aneurysm, which can be the preferred method for entrapped abdominal aortic aneurysm. Abdominal ultrasound is of great value in the diagnosis and differential diagnosis of obstructive diseases of the inferior vena cava, as well as the judgment of treatment effect.