Ventilators can be categorized into non-invasive and invasive ventilators. If it is a non-invasive ventilator, it usually does not cause pain and if it is an invasive ventilator, it may be painful. The main function of a ventilator is to assist the patient in breathing by pumping fresh oxygen into the body while helping the body to expel waste gases such as carbon dioxide. Ventilators can prevent and treat respiratory failure, reduce complications, save and prolong the patient’s life, and play an important role in critically and acutely ill patients. If it is a non-invasive ventilator, it is mainly connected via a mask or other methods, which does not cause damage to the patient and usually does not cause pain. However, if it is an invasive ventilator, it needs to be connected through the mouth, nose, tracheal tube or tracheotomy, etc. Some pain and discomfort may exist, but anesthetic will be used during the operation, which may reduce the pain felt by the patient. If a ventilator is required, it should be used according to medical advice.