Finding a bump on your skull can be surprising, often raising questions about its origin. Many such bumps are harmless, simply part of your natural bone structure, while others stem from different causes. This article explores common anatomical variations and other factors that can lead to these formations.
Normal Skull Anatomy and Benign Growths
Many perceived skull bumps are simply normal anatomical features. One such feature is the external occipital protuberance (EOP), a bony bump at the back of the skull where the neck meets the head. This midline prominence on the occipital bone serves as an attachment point for the nuchal ligament and trapezius muscle. Its prominence varies significantly among individuals.
Another common anatomical variation is the sagittal keel, or sagittal torus. This appears as a thickening along the midline of the frontal or parietal bones where they meet. It is a rounded, lower elevation. A small percentage of modern humans exhibit this feature, though its function remains unknown.
Beyond these typical structures, benign bony growths called osteomas can also appear on the skull. These non-cancerous bone tumors grow slowly and are often found on the skull or jawbone. Most osteomas do not cause any symptoms. They are typically round or oval, hard, and firmly attached to the underlying bone.
Causes Beyond Normal Anatomy
Skull bumps can also result from factors other than inherent bone structure. Injuries are a frequent cause, leading to temporary swellings. A common example is a hematoma, which occurs when blood collects under the skin following a blow to the head, creating a visible and palpable bump. This swelling is temporary, resolving as the body reabsorbs the trapped blood.
Other non-cancerous lumps include sebaceous cysts, which are fluid-filled sacs developing under the skin due to blocked oil glands. These cysts are soft to the touch and movable. Lipomas are another type of benign lump, consisting of fatty tissue that forms a soft, rubbery mass beneath the skin. Infections can also lead to localized swelling or abscesses on the scalp, which may feel like a bump.
When to Consult a Doctor
While many skull bumps are harmless, certain characteristics warrant a medical evaluation. You should consult a doctor if a bump appears suddenly after a head injury and is accompanied by symptoms such as dizziness, confusion, or changes in consciousness. A medical opinion is also advisable if the bump is painful, grows rapidly, or changes in color.
Any skull bump that feels warm to the touch, is accompanied by fever, or shows signs of infection like redness or pus, should also be assessed by a healthcare professional. Neurological symptoms such as persistent headaches, vision changes, or weakness alongside a skull bump also signal the need for prompt medical attention. A doctor can accurately diagnose the cause of the bump and recommend appropriate management.