The different heights of the two nipples of boys may be caused by physiological and pathological factors. 1. Physiological factors: usually due to asymmetrical development of the pubertal organism, for example, one side of the breast is underdeveloped, while the other side of the development of normal, there will be a high and low situation. Secondly, you can also observe the boy’s posture, sitting posture, walking posture, the height of the left and right shoulders, if it is a problem of the sternum and cervical vertebrae, it will also lead to the left and right nipples in the visual high and low. 2. Pathological factors: during puberty, when the body’s estrogen level is relatively elevated, it can lead to breast development disorder, appearing as one big mammary gland and one small one, which leads to two nipples of different heights. The causes of relatively elevated estrogen levels are more numerous, such as testicular tumors, endocrine diseases, etc., leading to a decrease in androgen secretion, which results in a relatively elevated level of estrogen in the body. At the same time, trauma, breast hyperplasia, breast cancer, breast inflammation can also cause asymmetry between the two sides of the mammary glands, thus manifesting as different nipple heights. It is suggested that when the symptoms are serious, you should go to the breast surgery department of regular hospitals, do breast ultrasound examination, make a clear diagnosis and actively treat under the guidance of doctors.