Dense hilar shadow refers to a denser shadow in the hilar region of the lung, which is an occupying lesion detected by imaging, but not necessarily lung cancer. In addition to lung cancer, it is also seen in other conditions, such as inflammation of the lungs caused by lung infections, including bacteria, viruses, mycoplasma, chlamydia, rickettsia, and fungi, as well as Mycobacterium tuberculosis infection. Other cardiovascular diseases, such as hypertension and coronary artery disease, including pulmonary stasis and left heart failure, may also present with a thickening of the hilar shadow. The diagnosis can be made clinically by further enhancement of CT scan and MRI of both lungs, as well as electrocardiogram, cardiac ultrasound and myocardial enzyme profile.