A patch of yellowish skin on the chest may be due to post-inflammatory hyperpigmentation, damaged capillaries, subcutaneous hemorrhage and so on. 1. Post-inflammatory hyperpigmentation: a piece of skin on the chest turning yellow may be due to fungal infections, various dermatitis after the inflammation subsides, the local pigmentation, there will be symptoms of yellowish skin. 2. Damaged capillaries: patients with damaged capillaries will have symptoms such as redness and inflammation of the skin, with the development of the disease will have yellow skin, some patients will be accompanied by itching. 3. Subcutaneous hemorrhage: after subcutaneous hemorrhage, the hemoglobin in the blood is swallowed and degraded by lysosomes to iron-containing hemosiderin, which is brownish-yellow in color, so the skin will look yellow. When you find a piece of skin turning yellow on your chest, you should go to the hospital in time for examination and receive professional doctor’s examination and diagnosis.