Patients with sleep apnea syndrome are usually advised to wear a respirator is during sleep and not during waking hours. There are certain side effects of using a ventilator, first of all, because wearing a ventilator requires a nasal mask or nasal pillow in order to contact the skin, and some patients have sensitive skin, which may involve damage, allergies, itching and other skin problems. There is also the respirator will give pressure, there will be wind blowing inside the respiratory tract, if the nasal mask cover is not tight, leakage, will have a certain impact on the eyes, may make it tear, inflammation. If the airflow pressure given by the ventilator is too high, it can cause problems of bloating and can be very uncomfortable. In conclusion, the ventilator has no particularly obvious side effects, but mainly some local reactions, such as contact with the skin. Some patients may experience discomfort after using the ventilator, especially on the first night, and it may even cause insomnia. Some patients may feel tense and claustrophobic when they put on the nasal mask. The side effects can be reduced or avoided by adjusting the size of the nasal mask, the tightness and pressure level of the mask, or by replacing the mask with a better material.