Pain in the lower right chest belongs to the category of differential diagnosis of chest pain, which usually requires differentiating whether it is a male or a female patient. For example, male patients should be distinguished as high-risk chest pain, moderate-risk chest pain, and mild-risk chest pain. High-risk chest pain with pain under the right side of the chest is commonly associated with right-sided tension pneumothorax, pulmonary infarction, aortic coarctation, and acute myocardial infarction. Intermediate-risk chest pain may have right-sided pleural effusion, right-sided lung infection, and right-sided massive pneumonia. Mild-risk chest pain may include herpes zoster on the right side, costochondritis on the right side, osteoarthritis on the right side, and acute cholecystitis may also have diffuse and spreading pain in the lower right chest. Women will also consider breast-like conditions, such as acute mastitis and tumors, among other factors.