The white part of the eye, i.e. the conjunctiva and the sclera, and the sudden congestion of the white part of the eye may be caused by physiological phenomena, or it may be related to ocular inflammation, ocular trauma and ocular foreign body injury. 1. Physiological phenomenon: patients with abnormal emotional excitement, prolonged use of the eyes, etc. can cause sudden congestion of the whites of the eyes, generally ease the emotions, relax the eyes, the patient’s conjunctival congestion phenomenon can be gradually relieved. 2. Ocular inflammation: scleritis, conjunctivitis and other ocular inflammation patients, under the stimulation of inflammation, patients may appear conjunctival congestion. 3. Ocular trauma: when the patient suffers blunt contusion in the eye caused by a fall, a car accident, or a ball game, the patient may also suffer from sudden congestion of the conjunctiva, which may be accompanied by subcutaneous bruising and swelling of the eyelids. 4. Eye foreign body injury: glass, gravel, bamboo sticks and other foreign objects into the eye surface, the patient in the foreign body stimulation, may also appear in the conjunctiva congestion and other uncomfortable symptoms. It is recommended that patients with sudden congestion of the eyes accompanied by other discomforts should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.