Children with bruises on the forehead, there are two reasons, as follows: 1, hyperthyroidism: after the high-functioning metabolism, the blood flow on the forehead will increase, resulting in the exposure of blood vessels on the forehead. 2, especially thin: subcutaneous fat is less, the blood vessels on the forehead will be especially easy to see, especially in the exercise, the blood vessels on the forehead will be dilated, so people will look at the local bruises exposed more obvious. If the child has no obvious symptoms of maladjustment, you can not do special treatment.3, pathological factors: If most of the bruises on the forehead are caused by venous factors, and part of it is heart disease lesions, malnutrition, venous lesions and other causes of bruises on the forehead, parents should take their children to the hospital in time for examination to avoid adverse consequences.