The pain in the toe for many years is actually “abdominal aortic aneurysm”. Sun old lady, over the past few years often inexplicable dizziness, weakness, accompanied by intermittent toe, always a few times a year sudden pain, severe times, the pain can not sleep at night. Recently, Mrs. Sun came to the hospital to see. At first, Mrs. Sun did a lot of tests, but could not find the root cause of the problem. Then, it was suggested to take a look at the vascular surgery department. The old lady was lying there, looking breathless. Recalling the first time I saw Mrs. Sun in the ward, she said that there were no symptoms before the toe pain attack, and the location of the pain was not fixed, sometimes the pain was in the left two toes, and sometimes in the right foot, which was erratic. Sometimes the pain was in the left toe and sometimes in the right foot, so it was erratic. I didn’t know when the next attack would occur, so it was painful. I carefully examined Mrs. Sun’s feet. “The skin temperature was normal and the dorsalis pedis artery pulsation was normal, but the ventral surface of the 2 toes on the right foot was abnormally blue-purple.” From a professional point of view, this is caused by toe ischemia, clinically known as “blue toe syndrome”, mostly due to small thrombus detached from the body of unknown origin, causing embolism, spasm of the small arteries of the toe, thus causing ischemia. It is understood that Mrs. Sun suffers from hyperlipidemia and has a history of secondhand smoke for many years because her partner smokes. At first, it was considered whether Mrs. Sun had atrial fibrillation because patients with atrial fibrillation are prone to thrombus detachment causing small artery embolism, but the previous examination had ruled out this possibility. Subsequently, upon examination, a pulsating mass was evident in the small abdomen of Mrs. Sun, which was suspected to be an abdominal aortic aneurysm. Sure enough, according to the abdominal CT, the vessel where the mass was located was 37 mm in diameter, more than twice the diameter of the normal segment of the vessel (18 mm). The asymmetrical bulge of the vessel there was a greater risk of rupture, and then, in cross-section, there was a large amount of attached thrombus. Mrs. Sun was eventually diagnosed with an abdominal aortic aneurysm, as well as distal arterial embolism caused by detachment of the appendage thrombus. Perhaps people are unfamiliar with abdominal aortic aneurysms, but in fact, the famous scientist Albert Einstein, the famous geologist Li Siguang and the French leader of World War II, General de Gaulle, passed away because of ruptured abdominal aortic aneurysms. An abdominal aortic aneurysm is a permanent, limited arterial dilatation in which the diameter of the dilated segment of the artery is 1.5 times the diameter of the adjacent segment. This is often associated with a feeling of abdominal “pulsation” or palpation of a pulsating mass, distal artery embolism due to dislodgment of the attached thrombus, and sometimes abdominal pain, which often indicates a dramatic expansion or even rupture of the aneurysm. So, what is the relationship between toe pain and abdominal aortic aneurysm? Because of the local expansion of the vessel, blood flow becomes turbulent, and the slow flow closest to the arterial wall forms a thrombus, which is medically known as an appendage thrombus. The clot is not tightly adherent and is sometimes “washed out” by a newly formed clot or a sudden rise in blood pressure. The dislodged thrombus flows to the lower extremity with the blood flow, causing embolism of the lower extremity artery. This is what happened to Mrs. Sun when a thrombus from the abdominal aorta “washed down” to her toe, blocking a small artery and causing pain in her toe. Abdominal aortic aneurysm is often referred to as a “time bomb” Generally speaking, the aneurysm diameter is less than 4 cm, the probability of rupture is only 10%, while as the aneurysm continues to expand, close to 4-7 cm, the probability of rupture rises to 25%, 7-10 cm, the probability of 46%. If the tumor is more than 10 cm in diameter, there is a 61% probability. “The larger the tumor, the faster it expands, eventually leading to rupture.” Once the tumor ruptures, the total mortality rate is about 90 percent, and even if the tumor is brought to the hospital in time, the mortality rate is greater than 50 percent. The risk of rupture is higher in specific populations such as advanced age, smoking, aneurysm-attached thrombosis, heart disease and a history of stroke. Although abdominal aortic aneurysms are dangerous, they are insidious, rarely present with clinical symptoms, and are difficult to detect on routine physical examination. The detection rate is only 29% for aneurysms 3-3.9 cm in diameter, 50% for those 4-4.9 cm in diameter, and 75% for those larger than 5 cm. It is reported that the incidence of abdominal aortic aneurysm increases year by year in people over 50 years of age, and it is more likely to occur in middle-aged and elderly men, with the incidence in men being 2-6 times higher than that in women. The incidence rate for smokers is 7 times that of non-smokers, and for those with a family history, the incidence rate for their members is 12%-195. At present, considering that Sun’s aneurysm is not too large, she is temporarily treated with conservative medication and regular follow-up observation. The identification of toe pain from the vascular point of view can be divided into vascular, neurological, and mixed types. Neurological may be, for example, diabetes, intervertebral disc lesions, etc., causing abnormal sensation in the toe, which can be manifested as local numbness, burning sensation, foreign body sensation, etc., in addition to pain. Vascularity, on the other hand, can manifest as acute ischemia with sudden onset of pain, which is often the result of vascular embolism. It also includes atherosclerosis, such as walking two hundred meters and starting to have foot pain, which may be due to a decrease in the blood supply capacity of the blood vessels. “Especially in the elderly, the identification in this area is very difficult.” If you have a sudden onset of pain, it’s important to seek prompt medical attention. For how to prevent abdominal aortic aneurysms, the first step is to do absolute smoking cessation; the length of time you smoke is more harmful than the number of cigarettes you smoke. Second, specific groups of people should have regular checkups. Routine physical examinations in Europe and the United States include vascular examinations, including targeted screening examinations for abdominal aortic aneurysms in men over 65 years of age, men over 55 years of age with a family history of smoking, and women over 65 years of age with a family history or a history of smoking. In addition, regular consultation with a specialist in vascular surgery should not be overlooked.