If patients experience cardiac discomfort during deep breathing, the following conditions are usually taken into consideration, such as patients with cardiogenic factors, such as coronary artery disease, unstable angina, acute myocarditis, pericarditis, rheumatic heart disease, valvular disease of the heart, hypertrophic obstructive cardiomyopathy, will have clinical manifestations of chest tightness, shortness of breath, palpitations and, in severe cases, pain in the precordial region during deep breathing. For diseases of the respiratory system, such as chronic bronchitis, bronchiectasis, chronic obstructive pulmonary emphysema, pulmonary heart disease, and pulmonary hypertension will also have these symptoms. Acute infections of the respiratory system, such as acute bronchitis, massive lung infections, and pleurisy, can have significant pain in the precordial region and respiratory system during deep breathing. In addition, for some patients with plant nerve disorders, such as cardiac neurosis, they may also self-report feeling pain in the heart during deep breathing.