Plaques on the stomach may be caused by trauma, sweat spots or age spots. 1. Trauma: If the patient’s subcutaneous blood vessels rupture and bleed due to trauma, purple or purple-black bruises will be formed on the stomach, and the local area may also have slight pressure pain. 2. Sweat spot: mostly related to Malassezia infection, often occurring on the belly and other parts of sebum secretion, when sweat spot appears, it may lead to the appearance of brown round spots on the belly, accompanied by slight itching. 3. Age spots: also known as seborrheic keratosis, mostly in the elderly, occurring in the face, may also be extended to the belly, so there will be a plaque on the stomach. If there are plaques on the stomach, it is recommended to go to the hospital, clear causes under the guidance of the doctor for treatment.