Puffy eyes are mainly edema of the subcutaneous tissues of the eyelids. The subcutaneous tissues of the eyelids are loosely structured, and various factors that cause subcutaneous tissue edema can cause puffiness in the eyes. One is lack of sleep and fatigue, which can slow blood circulation, stagnate blood in the veins, and cause edema of the eyelid tissue due to fluid leakage from the blood vessels, resulting in puffy eyes. The second is exposure to certain substances that cause eyelid skin allergies and tissue edema, resulting in puffy eyes. Third, external forces, such as trauma, cause eyelid tissue damage and edema, resulting in puffy eyes. Fourth, kidney system disease, abnormal kidney metabolic function, sodium and water retention, usually in the morning when you get up, the eyelids and face edema, causing eye puffiness. Fourth, significant weight gain in a short period of time, such as female pregnancy and glucocorticoid action, overloads the heart, stagnates blood, and fluid in the blood leaks into the tissues, causing puffy eyes. Fifth, people with heart disease system, cardiac insufficiency, heart overload, blood stagnation, resulting in tissue edema, which can cause eye puffiness. Sixth, idiopathic edema, mostly seen in women, especially around the menstrual period, can also lead to puffy eyes, etc. In summary, if eye swelling occurs, because of its many causes, it is recommended to go to the hospital for examination to clarify the cause and treat it symptomatically.