Most dips, ridges, and subtle indentations you can feel on your skull are simply part of your normal anatomy. The human skull is not a perfectly smooth sphere; it is made up of several bony plates joined by suture lines, and these plates vary in thickness from person to person and even from one spot to another on the same head. That said, a dip that appears suddenly, grows over time, or comes with other symptoms can sometimes signal something that needs medical attention, from old trauma you may have forgotten to bone-thinning conditions and, in rare cases, tumors.
Normal Skull Contours You Might Mistake for a Problem
Your skull is assembled from roughly two dozen bones, and the seams where they meet (called suture lines) create ridges and shallow grooves you can often feel through your scalp. Along the top of your head, a subtle midline ridge runs front to back where the two large parietal bones meet. At the back, you can usually feel a bony bump called the external occipital protuberance, and just above each ear the temporal bone meets the parietal bone at a junction that can feel like a slight step or depression. None of these are abnormal.
Many people go years without noticing these contours and then discover them during a haircut, a new close-cropped hairstyle, or just idly running their fingers over their scalp. Weight loss can also make skull features more prominent because you lose subcutaneous fat that once padded the area. Aging plays a role too: the skull itself changes shape subtly over decades, and scalp tissue thins, making bumps and dips that were always there more noticeable to the touch.
Indentations Present from Birth
Some skull dips are congenital, meaning they were there from the very beginning. During delivery, the pressure of the birth canal or the use of forceps or vacuum extraction can leave a shallow depression in a newborn’s soft skull. These so-called “ping-pong” fractures are actually inward bucklings of the flexible neonatal bone, and in most cases they resolve on their own as the baby grows. In rarer instances, the indentation has nothing to do with the delivery itself. One case report described a newborn with an ovoid indentation behind the right coronal suture that was attributed to the position of the baby’s hand pressing against the skull in the womb.1PubMed Central. Congenital skull indentation: a case report and review of the literature If you have had a dip in your head for as long as you can remember, it is worth considering that it may have been present since birth and simply represents a harmless variant in how your skull formed.
Trauma and Depressed Skull Fractures
A blow to the head can push a piece of the skull inward, creating what doctors call a depressed skull fracture. This typically involves both the outer and inner layers of the skull bone being driven inward by blunt force.2PubMed Central. A Rare Case of a Depressed Inner Table Fracture Without an Outer Table Fracture Following Trauma in a 20-Year-Old Male Patient The resulting dip can be small enough that you only notice it when touching your scalp, or large enough to be visible. Sometimes people sustain a head injury in childhood, recover without incident, and only discover the residual indentation years later when they happen to feel it.
Not every depressed fracture needs surgery. If the bone fragment is not pressing deeply enough to threaten the brain underneath, doctors may simply monitor it. Deeper depressions, those contaminated by an open wound, or those associated with neurological symptoms typically need surgical elevation of the bone fragment. If you know you had a significant head injury in the past and you can feel a dip in that area, there is usually no new cause for alarm, but mentioning it to your doctor during a routine visit is reasonable.
Dips After Brain Surgery
Neurosurgical procedures are among the most common medical reasons for a palpable skull depression. During a procedure called a burr hole trepanation, surgeons drill one or more small holes through the skull to drain fluid or relieve pressure.3Journal of Medical Devices. Development and Mechanical Testing of Implant for Cranial Reconstruction After Burr Hole Trepanation Even when these holes are plugged with small implants afterward, you can sometimes still feel a slight depression at the site. Larger openings made during craniotomy or craniectomy (where a whole section of skull is temporarily or permanently removed) can leave more noticeable contour changes.
A particularly dramatic version of this is called sinking skin flap syndrome. After a decompressive craniectomy, where a large portion of skull is removed to give a swelling brain room to expand, the area where bone is missing can visibly sink inward once the swelling resolves. Atmospheric pressure pushing on the unprotected scalp causes the skin flap to cave in, and this can actually impair blood flow and brain function in the area underneath.4PubMed. Sinking Skin Flap Syndrome After Decompressive Craniectomy: A Case Report People with this condition often notice neurological improvement once the missing bone is replaced with an implant, which is why follow-up cranioplasty is standard after decompressive craniectomy.
Age-Related Skull Thinning
If you are in your 60s or older and notice a soft or thin-feeling area on the sides of your skull near the top, age-related bone thinning is a plausible explanation. A condition known as biparietal osteodystrophy involves progressive thinning of the parietal bones, the two large plates that form the upper sides and roof of the skull. Current evidence points to this being a form of involutional osteoporosis affecting the skull rather than a congenital abnormality.5PubMed Central. Biparietal osteodystrophy in an 86-year-old woman: An incidental finding following minor head trauma It is usually discovered incidentally, often after a CT scan ordered for another reason, like a minor bump to the head.
The thinning itself is typically painless and gradual enough that people do not notice it directly. What they may notice is that the area feels slightly softer or less bony than the rest of the skull, or that a minor bump causes more pain than expected because there is less bone to absorb the impact. In most cases, no treatment is needed, but your doctor should know about it because thinner bone is more vulnerable to fracture.
Bone Diseases That Reshape the Skull
Paget’s disease of bone is a chronic condition in which the normal cycle of bone breakdown and rebuilding goes haywire. Bone is resorbed and then replaced with structurally abnormal bone that is weaker, larger, and more prone to deformity. The pelvis, skull, and spine are the three most frequently affected areas.6PubMed Central. Paget’s Disease: Skeletal Manifestations and Effect of Bisphosphonates In the skull, Paget’s disease tends to cause overall enlargement rather than a discrete dip, but the combination of thickened areas and weakened areas can produce irregular contours. If you notice your head seems to be changing shape and your hat size is increasing, Paget’s disease is something your doctor can test for with a simple blood test and imaging.
A far rarer condition is Gorham-Stout disease, sometimes called vanishing bone disease. In this disorder, blood-vessel-like structures proliferate within bone and progressively destroy it. It can affect one bone or several, and the skull is one of the possible sites.7PubMed Central. Vanishing bone disease (Gorham-Stout syndrome): A review of a rare entity A case involving skull-base involvement in a 27-year-old man illustrates how destructive the disease can be when it progresses unchecked; the patient developed serious neurological complications from progressive bone loss at the base of the skull.8PubMed Central. Fatal Progression of Gorham-Stout Disease with Skull Base Osteomyelitis and Lateral Medullary Syndrome Gorham-Stout is genuinely rare, and if you are reading this article because you noticed a dip in the shower, it is very unlikely to be the explanation. It is included here because an indentation that is clearly growing over weeks or months warrants prompt imaging.
Skull Growths and Lesions
The skull can develop both benign and malignant growths, and some of these eat away at bone from within, creating a dip that you feel on the outside. Benign fibro-osseous lesions, a group that includes fibrous dysplasia and ossifying fibroma, are rare but can erode the skull enough to cause a visible indentation. One reported case involved a 16-year-old boy who noticed an indentation on his skull; imaging revealed that a benign lesion underneath was progressively eroding the bone.9PubMed Central. Fibro-osseous lesion of the cranium in an adolescent patient
Skull vault tumors in adults span a wide spectrum. A diagnostic review categorizes them into groups based on what they look like on imaging: some dissolve bone (lytic lesions), some create extra bone (sclerotic lesions), and some grow through the middle layer of the skull (transdiploic lesions).10PubMed Central. Imaging of skull vault tumors in adults The lytic category is the one most relevant to skull dips because bone destruction can produce a soft spot or depression you can feel. Common lytic lesions include epidermoid cysts (benign), eosinophilic granuloma (benign, more common in children), hemangiomas (benign blood-vessel tumors), and metastatic cancer deposits.
Multiple myeloma, a blood cancer originating in the bone marrow, is a well-known cause of multiple “punched-out” skull lesions that can be felt as soft spots.11PubMed Central. A case of multiple myeloma presenting as scalp swelling with intracranial extension When a CT scan shows multiple bone-dissolving skull lesions rather than a single one, the odds of malignancy go up substantially.12PubMed Central. Decoding calvarial lesions: Contemporary neurosurgical management integrating radiological and histopathological features This is why any new, unexplained soft spot or dip in the skull, especially if there seem to be more than one, should be evaluated rather than ignored.
When You Should See a Doctor
A dip you have had your entire life, or one that clearly corresponds to old trauma or past surgery, is almost always benign. The situations that deserve prompt medical attention fall into a few recognizable patterns:
- New and growing: A depression that was not there six months ago, or one that seems to be getting larger or deeper, could indicate an underlying lesion eroding the bone.
- Painful or tender: Normal skull contours do not hurt when you press on them. Pain, redness, or warmth over a skull dip suggests inflammation, infection, or an active bone process.
- After recent head trauma: If you hit your head and now feel a new indentation, even without a visible wound, you could have a depressed fracture that needs imaging.
- Accompanied by neurological symptoms: Headaches that are worsening, vision changes, seizures, weakness, or personality changes alongside a skull indentation are red flags.
- Multiple soft spots: A single dip is far more likely to be benign than several scattered depressions, which raise concern for conditions like multiple myeloma or metastatic disease.
Your primary care doctor can order a CT scan of the head, which is the single most useful test for evaluating a skull depression. CT shows bone detail far better than a standard X-ray and can distinguish a normal anatomical variant from a fracture, a lytic lesion, or thinning bone in a matter of minutes.
How Skull Dips Are Repaired
When a skull defect does need repair, whether from trauma, surgery, or a destructive bone lesion, the procedure is called cranioplasty. The goal is to restore the skull’s protective barrier and, often just as importantly for the patient, to restore a normal head contour. Modern cranioplasty has come a long way from the days of generic bone-cement patches shaped by hand in the operating room.
Today’s implants are often custom-made using 3D printing and CT data from the individual patient’s skull. Materials include titanium, a synthetic polymer called PEEK (poly-ether-ether-ketone), and hydroxyapatite-titanium composites that combine metal strength with a surface that encourages bone to grow into it.13PubMed. Cranioplasty with customized titanium and PEEK implants in a mechanical stress model Custom-made 3D-printed PEEK implants have shown good cosmetic and functional outcomes while shortening operating time compared to hand-sculpted implants.14PubMed Central. Three dimensional custom-made PEEK cranioplasty Hydroxyapatite-titanium implants have also accumulated a solid track record, with one large U.S. series confirming their safety and effectiveness.15PubMed. Skull Reconstruction Using a Custom-Made, Three-Dimensional-Printed, Hydroxyapatite-Titanium Cranioplasty Implant: Largest Single-Center U.S. Experience
For smaller defects, like those left after burr hole surgery, smaller plugs or caps designed to snap into the hole are available.3Journal of Medical Devices. Development and Mechanical Testing of Implant for Cranial Reconstruction After Burr Hole Trepanation Cranioplasty is not always purely functional. Many patients pursue it because a visible skull depression is a source of self-consciousness or anxiety, and restoring a smooth contour can make a genuine difference in quality of life.
Intentional Skull Shaping Through History
Not every unusual skull shape is accidental or pathological. For thousands of years across multiple cultures, people deliberately reshaped infant skulls for cultural, social, or aesthetic reasons. In the Tiwanaku civilization of ancient Bolivia, for instance, mechanical devices were applied to babies’ heads within the first months of life, before the skull bones had fully hardened. Two main styles were practiced: tabular deformation (using flat boards to flatten the front or back of the skull) and annular deformation (using tight wrappings to produce a more elongated, conical shape).16PubMed Central. Artificial cranial deformation in Tiwanaku, Bolivia These practices permanently altered the shape of the frontal, parietal, occipital, and temporal bones, depending on the technique and how long the pressure was applied.
Research on skulls modified this way shows that the deformation changes how the bones relate to each other structurally, altering the normal patterns of how different parts of the skull grow in coordination.17PubMed Central. Morphological consequences of artificial cranial deformation: Modularity and integration The practice existed independently in cultures across South America, Mesoamerica, Europe, Africa, and parts of Asia. While no mainstream culture practices intentional cranial deformation today, it is a vivid reminder of how malleable the infant skull is and how external pressure during the critical growth window can create permanent changes in head shape. It also helps explain why some families notice inherited patterns of skull contour: even without deliberate reshaping, the position a baby sleeps in or the pressures of a long labor can leave lasting impressions on a developing skull.