5. Respiratory distress
In a late stage of the disease, patients may experience episodes of respiratory distress. In some cases, they may even faint due to a reduction of oxygen saturation in the blood. Patients with advanced COPD may start experiencing respiratory distress when they do simple house chores and other day-to-day activities. One of the giveaway signs is tachypnea or accelerated breathing, along with a sensation of running out of breath.