Encyclopedic entry. We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions.
Myocardial infarction (heart attack). This reduction in blood flow through heart blood vessels causes the death of heart muscle cells. Though similar to angina chest pain, a heart attack is usually a more severe, crushing pain usually in the center or left side of the chest and is not relieved by rest. Sweating, nausea, shortness of breath, or severe weakness may accompany the pain. Myocarditis.
A chest contusion, or bruise, is caused by a fall or direct blow to the chest. Car crashes, falls, getting punched, and injury from bicycle handlebars are common causes of chest contusions. A very forceful blow to the chest can injure the heart or blood vessels in the chest, the lungs, the airway, the liver, or the spleen. Pain may be caused by an injury to muscles, cartilage, or ribs. Deep breathing, coughing, or sneezing can increase your pain. Lying on the injured area also can cause pain. Follow-up care is a key part of your treatment and safety.