Gross disease is rarely symptomatic until infection occurs in the sinus tract. Typically, there are tiny pits in the caudal midline without any sensation. The pits have tiny holes, some of which are difficult to access even with a tear sac probe. This is the primary sinus tract, 5 to 6 cm from the anus. superficial abscesses form locally after infection and discharge pus after self-rupture or surgical incision. The abscess discharges thin pus for a few days and then gradually heals, leaving a hard node. Another abscess may appear after another bacterial infection. The prognosis is not good if metastasis occurs in the case of carcinoma of the hairy sinus, and the 5-year survival rate is 51% as reported in the literature. The recurrence rate is 50%. Metastases in the inguinal lymph nodes are found in 14% of cases at the time of initial diagnosis. So, how should patients prevent the appearance of a small pit in the midline of the tail without any sensory symptoms? The following is a brief introduction: 1. Combine work and rest, and ensure 7-8 hours of sleep every day. 2, wash your hands regularly, bathe often, do not share towels and toiletries. 3, brush your teeth every day, rinse your mouth after meals. 4, do not smoke in public places, respect the right of non-smokers from passive smoking. 5.Drink less alcohol. 6.Pay attention to the safety of drinking water. 7, pay attention to drinking water hygiene. 8, the diet should be mainly cereals, eat more vegetables and fruits and potatoes, pay attention to the meat and vegetables. 9, often eat milk, beans and their products. 10, the diet should be light and less salt. 11, maintain a normal weight, avoid overweight and obesity.