 Vertical ridges. So if it's on the thumb, if you have those ridges on your thumb, according to Chinese medicine, you know, this is just fun to think about. It could be spleen, heart, or depression things. If it's on your first finger, index finger, it could be unhappiness. Middle finger, it could be nervousness and hyperactivity. Ring finger, it could be your heart broken or emotionally traumatized.