Esophageal cancer can cause symptoms such as chest tightness and shortness of breath, which may occur under the following conditions: 1. Severe anemia caused by esophageal cancer, patients with esophageal cancer often suffer from severe malnutrition due to inability to eat or little eating, resulting in nutritional deficiency anemia, and severe anemia can cause serious decrease in the function of blood to carry oxygen and lead to ischemia and hypoxia, resulting in chest tightness and shortness of breath, which is often a common symptom of patients with advanced esophageal cancer. 2.Esophageal cancer mass directly compresses trachea, human esophagus is next to trachea, so esophageal cancer mass can directly compress trachea and lead to narrowing of trachea and decrease of lung ventilation function, which can lead to breathing difficulty and symptoms such as chest tightness and shortness of breath. 3.Lung metastasis occurs in esophageal cancer, lung metastasis can occur in advanced esophageal cancer, which can damage lung function and lead to decrease of diffusion function of lung. The metastatic lung cancer can damage the lung function and cause the diffusion function of the lung to decrease. In addition, lung metastasis of esophageal cancer can also lead to lung infections such as obstructive pneumonia, and serious lung infections can also affect the oxygen exchange of lungs, both of which can lead to symptoms of chest tightness and shortness of breath.