There are many diseases that cause fundus hemorrhage, and the common causes of fundus hemorrhage are as follows: 1. Retinal vein obstruction: Patients often have a history of hypertension and atherosclerosis, and the clinical manifestation is sudden vision loss or blurred vision. Funduscopic examination shows a large number of flaky or flame-like hemorrhages in the area of venous obstruction, which may be accompanied by retinal edema and exudation. In the case of branch retinal vein obstruction, the fundus hemorrhage is usually localized to the area of vein obstruction, while in the case of central retinal vein obstruction, the fundus hemorrhage is extensive and severe. In case of branch retinal vein obstruction involving the macula or central retinal vein obstruction, patients may experience significant vision loss. 2, diabetic retinopathy: patients have a history of diabetes, some diabetic patients are not aware of it themselves, blood glucose test can be clearly diagnosed. The fundus hemorrhage in diabetic retinopathy develops gradually. In the early stage, the hemorrhage is only a small amount of punctate hemorrhage with microangioma, and as the disease progresses, punctate hemorrhage and exudation may appear. Once the lesion progresses to the proliferative stage or macular edema develops, the patient may show vision loss. If the retinal neovascularization leads to massive hemorrhage in front of the retina or vitreous hemorrhage, patients usually have sudden vision loss, and in serious cases, only the manual hand is visible. 3.Age-related macular degeneration: The site of fundus hemorrhage in age-related wet macular degeneration is usually confined to the macular area, and patients are mostly over 50 years old. The clinical manifestation is sudden vision loss with central visual impairment.OCT examination can find subretinal neovascular membrane (CNV) in macular area. Wet macular degeneration in late stage can also appear large subretinal hemorrhage or even vitreous hemorrhage, causing more serious visual impairment. 4. Other causes: Hypertensive retinopathy, nephropathic retinopathy, hematologic diseases and other systemic diseases can lead to fundus hemorrhage. Retinal fissures, eye trauma and other eye diseases can also lead to fundus hemorrhage. In conclusion, there are many causes of fundus hemorrhage, and different causes of fundus hemorrhage have different mechanisms, characteristics and treatment methods. Therefore, once fundus hemorrhage is detected, further examinations such as fundus angiography and OCT examination are needed to clarify the diagnosis and develop a more reasonable treatment plan.