Hyperostosis frontalis interna (HFI) is a condition in which there is an overgrowth of bone on the inner surface of the frontal bone, the bone that forms the forehead. It is a benign condition, meaning that it is not cancerous, and it does not usually cause any symptoms. However, in some cases, it can cause headaches, vision problems, or other neurological symptoms.
HFI is most commonly seen in women, and it is more common in older adults. The exact cause of HFI is unknown, but it is thought to be related to hormonal changes and genetic factors.
HFI is diagnosed with a physical exam and a CT scan or MRI of the head. Treatment is not usually necessary, but if symptoms occur, they can be treated with medication or surgery.