Swelling of the upper left eyelid without pain can be caused by a variety of factors, such as physiological factors or pathological factors, such as granuloma, kidney function abnormalities can be triggered. 1. Physiological factors: due to drinking too much water at night, or sleeping in an improper posture caused by the left upper eyelid pressure, resulting in poor blood circulation in the eye triggered by the symptoms. 2. Pathological factors (1) Granuloma: this is a common eye disease, such as using unclean hands to touch the eye or using irritating cosmetics, there will be swelling of the upper left eyelid without pain when pressed. (2) abnormal renal function: if the patient suffers from renal function disease, due to the decline of glomerular filtration function, causing the patient to appear sodium retention phenomenon, the body’s water will also increase, which will also appear in the phenomenon of the left upper eyelid swelling and pressure without pain. Swelling of the upper left eyelid without pain can also be seen in other causes, after the onset of the disease should go to the hospital to clarify the cause, under the guidance of the doctor’s medication.