Emphysema, slow-onset lung, is known by its academic name Chronic obstructive pulmonary disease (COPD). It is a global pathology of aging, mainly associated with an abnormal inflammatory response of the lungs to harmful gases or harmful particles. Among the most common harmful irritants come from cigarette smoke, biofuel smoke. Its prevalence is 7.8-20%. The epidemiology of pulmonary hypertension (PH) in patients with COPD is not known. Current studies estimate that at least about 1 in 4 COPD patients will have pulmonary hypertension or pulmonary heart disease. The main symptoms in patients with COPD-related pulmonary hypertension or pulmonary heart disease are fatigue, dyspnea, chest tightness and shortness of breath after activity, chest pain, abdominal distention and lower extremity edema. Right heart failure and decreased cardiac output may occur at this stage if consultation has not yet begun. This stage may progress to pre-syncope or even syncope. As the process progresses further, shock and death can occur. Early detection is not easy clinically because early symptoms are insidious and some of them overlap with the lung disease itself. Therefore, patients with COPD need early detection of pulmonary hypertension by regular electrocardiogram, chest X-ray, cardiac ultrasound and other related examinations. If necessary, a right heart catheterization is required. This is because right heart catheterization is the gold standard for the diagnosis of pulmonary hypertension. Cardiac catheterization provides an accurate measurement of mean pulmonary artery pressure for the diagnosis of pulmonary hypertension and measurement of pulmonary capillary wedge pressure to determine the presence of pulmonary venous hypertension. COPD-related pulmonary hypertension is usually mild. Smoking cessation and oxygen therapy are still the only proven treatments for COPD and are indicated for patients with COPD-associated pulmonary hypertension. In some patients with COPD-associated pulmonary hypertension, treatment with pulmonary hypertension-targeted drugs such as PDE5 inhibitors and prostacyclin analogs is required in parallel with the treatment of the underlying lung disease. In conclusion, COPD-associated pulmonary hypertension needs to be brought to the attention of the majority of patients with chronic lung disease, and early screening and early treatment is still the key.