Most parents and doctors hope that funnel chest can heal on its own, but the truth is that most cases of funnel chest cannot heal spontaneously. Imagine if it's a small sapling that has grown crooked from a young age, already deformed, with the sternum indenting inward and backward. As the chest continues to grow, especially during puberty, the funnel chest will become more and more pronounced. Just like a crooked sapling, if it is not corrected, as it grows, the indentation and deformity will become more prominent. Of course, there is an exception. Some children are found to have funnel chest within the first year after birth, which may be due to the pressure on the sternum from the arms and legs during pregnancy while in the mother's womb. We know that children are curled up in the womb, and this positioning of the arms and legs in front of the chest can also cause compression of the chest cavity, leading to an inward deformity of the sternum. However, after birth, as the arms and legs stretch out and the pressure causing the indentation on the chest is relieved, the deformity of the indented sternum may gradually improve. However, most cases occur before the age of one, and the likelihood of this happening decreases significantly after one year of age.