The correlation between back fever and mid-stage esophageal cancer is not large. Mid-stage esophageal cancer usually does not manifest back fever, but rather symptoms such as progressive dysphagia, persistent retrosternal pain or back pain. Back fever may be a physiological factor or a pathologic factor such as dorsal fasciitis or hyperthyroidism. If there is only one manifestation of back fever, it is usually not mid-stage esophageal cancer, and it may be caused by physiological factors, such as high temperature, wearing too thick or too tight clothes, strenuous exercise, etc. This is a normal phenomenon, which can be relieved by supplementing water, wearing loose clothes and taking proper rest. If there are no such factors, back fever may be caused by inflammatory diseases, such as dorsal fasciitis, etc. Inflammatory reaction will lead to the secretion of inflammatory mediators and cause back fever; it may also be caused by endocrine metabolic diseases, such as hyperthyroidism, etc., due to the body’s metabolism to increase, which can cause back fever. If you suspect that back fever is caused by disease, it is recommended to go to the hospital in time to identify the cause of the disease and treat the symptoms.