A Skull X-Ray (AP & Lateral) is a type of plain X-ray (also called a head X-ray plain or cranial bone X-ray) that creates black-and-white images of the bones of the skull. “AP” (anteroposterior) is a front-to-back view, and “lateral” is a side view. These two angles help the radiologist assess the skull bones, facial bone outlines, and parts of the sinus areas for visible changes.

This test does not measure a blood value—instead, it looks for structural findings such as:

• Fractures or cracks in the skull bone
• Abnormal bone areas (such as lesions, thinning, thickening, or unusual growth patterns)
• Signs of sinus opacification (sinuses that look less air-filled than expected, which can happen with fluid, swelling, or infection)

What results can mean: A “normal” skull X-ray typically means there is no obvious skull fracture, major bone lesion, or clear sinus fluid level seen on these views. An “abnormal” result may show a fracture line, depressed area of bone, suspicious bone changes, or sinus haziness/opacification. Because plain films have limits—especially for the brain, subtle fractures, or complex facial injuries—your clinician may recommend a CT scan or MRI for more detail if needed.

The exam is quick and noninvasive. You’ll usually be asked to remove metal items (glasses, hairpins, earrings) that can block the view. The amount of radiation is relatively low, but tell your provider if you are pregnant or could be pregnant.

Doctors order a skull X-ray (AP and lateral views) when they need a fast, accessible way to evaluate the cranial bones after certain symptoms, injuries, or clinical concerns. While CT is more common for many head injuries today, a skull X-ray may still be used in select situations depending on the setting, age, symptoms, and availability of imaging.

Common reasons a provider may request a skull x-ray include:

Head injury or trauma—for example, after a fall, sports injury, or accident—especially when there is concern for a skull fracture (such as localized scalp swelling, tenderness over a specific area, or a concerning mechanism of injury).

Persistent head or facial symptoms where bone involvement is a consideration, such as focal skull pain, a palpable bump, or a change in skull shape.

Evaluation of suspected bone lesions—when a clinician suspects a benign or malignant bone process involving the skull (based on symptoms, exam findings, or prior imaging).

Sinus-related concerns—a plain head/skull film may sometimes help detect sinus opacification (suggesting fluid or inflammation), although dedicated sinus imaging (often CT) is typically more informative.

Follow-up of known skull bone conditions—in certain cases, X-rays can help compare bone changes over time.

Seek urgent medical care for head injuries accompanied by red-flag symptoms such as worsening headache, repeated vomiting, confusion, seizure, fainting, weakness/numbness, severe drowsiness, or clear fluid from the nose/ears—these often require more advanced imaging like a CT scan.

• Skull fracture (linear, depressed, or basilar fracture—some types may not be fully assessed on plain film)
• Facial bone trauma with suspected skull involvement
• Sinusitis or sinus inflammation with possible sinus opacification (limited evaluation on skull X-ray)
• Benign skull bone lesions (e.g., fibrous dysplasia, osteoma)
• Paget disease of bone affecting the skull
• Bone tumors or metastatic lesions involving the skull (X-ray may show lytic or sclerotic changes)
• Multiple myeloma with skull involvement (may show “punched-out” lesions in some cases)
• Craniosynostosis in infants/children (premature fusion of skull sutures—often needs specialized imaging)

• Ruling out or confirming skull bone injury after trauma (supporting safe return to activity and appropriate treatment)
• Investigating unexplained skull pain, lumps, or changes in head shape
• Monitoring known skull bone conditions over time (when plain radiographs are appropriate)
• Supporting evaluation of suspected bone lesions to guide next steps (e.g., CT/MRI, referral, or biopsy planning)
• Assessing possible sinus-related fluid/opacification when symptoms suggest sinus disease and initial imaging is needed