What Does It Mean If the Back of Your Head Has a Dent?

September 27, 2025 •

4 min read

While many people experience slight skull irregularities, a noticeable dent in the back of your head can be a cause for concern. Interestingly, many of these indentations are harmless, while others may signal underlying issues. Understanding the potential causes is the first step to peace of mind.

Quick Summary

A dent in the back of your head can arise from multiple factors, including harmless normal skull variations, congenital conditions, past injuries, or benign cysts. It's often not a major cause for concern, but monitoring for other symptoms and consulting a doctor can provide clarity on the root cause.

Key Points

Normal Skull Asymmetry: Many dents are simply natural variations in bone structure and are not a cause for concern.
Infant Head Shape: In babies, a dent can be caused by positional plagiocephaly, often resolving on its own with growth and repositioning.
Trauma Warning: A dent following an injury should prompt a medical evaluation, especially if accompanied by headaches or dizziness.
Cysts and Tumors: Benign lumps like sebaceous cysts or lipomas under the scalp can sometimes create a feeling of a dent.
Seek Medical Advice: If the dent is new, growing, or accompanied by other symptoms, it is best to see a doctor for a proper diagnosis.

Understanding the Causes of Skull Indentations

Noticing a dent or dip in the back of your head can be alarming, but it's important to remember that the human skull is not perfectly symmetrical. A variety of factors, ranging from innocuous to more serious, can be responsible. For most individuals, the cause is entirely benign.

Benign and Normal Variations

Many dents are simply natural features of your bone structure. The occipital bone at the back of the skull has various ridges and bumps, and the area can feel uneven to the touch. This is perfectly normal and is often the most common explanation. Another cause is a condition known as positional plagiocephaly, which primarily affects infants. This occurs when a baby's head is consistently in the same position, such as during sleep, causing a flattened area that can appear as a dent. This condition often resolves itself as the infant grows and starts sitting up.

Injuries and Trauma

Traumatic injuries are a more obvious cause. Any forceful impact to the head, such as from a fall, a car accident, or a sports injury, can cause a skull fracture. Depending on the severity, this can result in a noticeable indentation. If you experience a dent following a head injury, especially with other symptoms like dizziness, nausea, or loss of consciousness, seeking immediate medical attention is crucial.

Congenital and Developmental Conditions

Certain conditions present from birth can also cause skull deformities. Craniosynostosis, for example, is a rare condition where the fibrous joints in an infant's skull (sutures) fuse prematurely. This can lead to an abnormally shaped head, including indentations, and often requires surgical intervention. Another less common condition, fibrous dysplasia, is a genetic bone disorder where normal bone is replaced by fibrous tissue. While it can occur anywhere, it can affect the skull and create areas of abnormal thickness or thinness, which may be felt as a dent.

Scalp and Soft Tissue Issues

Sometimes, the dent is not in the skull itself but in the soft tissues covering it. A sebaceous cyst, a slow-growing, non-cancerous lump, can form under the scalp. When the cyst is drained or naturally shrinks, it can leave behind a temporary indentation. Furthermore, a lipoma, a benign fatty tumor, can also cause a bump that might feel like a dent around its edges.

When to Seek Medical Attention

While many dents are harmless, it's important to consult a healthcare professional if:

The dent appears suddenly without any injury.
It is accompanied by other symptoms like headaches, dizziness, confusion, or changes in vision.
The dent is growing in size or changing in shape.
It is causing you significant pain or discomfort.
You have a child with an abnormal head shape and are concerned about craniosynostosis or plagiocephaly.

Comparison of Common Causes


Cause	Typical Onset	Related Symptoms	Requires Medical Attention?
Normal Skull Variation	Lifelong	None	No
Positional Plagiocephaly	Infancy	Flattened head, but generally no other symptoms	No (often resolves naturally), but consult for severe cases
Trauma/Injury	After an impact	Pain, headache, dizziness, nausea	Yes, especially with other symptoms
Fibrous Dysplasia	Childhood/Adolescence	Bone pain, fractures, abnormal growth	Yes, for diagnosis and management
Sebaceous Cyst	Any age	Non-painful lump that may have a central pore	No, unless it becomes infected or is cosmetic concern
Lipoma	Any age	Soft, movable fatty lump	No, unless large, painful, or cosmetic concern

Diagnostic Process

If you see a doctor about a dent, they will likely start with a physical examination of your head and scalp. They will ask about your medical history, any recent injuries, and when you first noticed the dent. Depending on their initial findings, they may order further diagnostic tests, which could include:

X-ray: To get a basic image of the skull bones.
CT Scan (Computed Tomography): To provide more detailed images of the skull and brain.
MRI (Magnetic Resonance Imaging): To get a clear picture of the soft tissues, including the scalp and any masses.

Treatment and Outlook

Treatment depends entirely on the underlying cause. For normal variations, no treatment is needed. Positional plagiocephaly in infants can be managed with repositioning techniques and sometimes a helmet. Injuries may require observation or more serious medical intervention, depending on the severity. Other conditions like fibrous dysplasia or congenital deformities will be managed by specialists. For cysts or lipomas, removal may be an option if they are bothersome or of cosmetic concern. For more information on cranial deformities, you can visit the Children's Hospital of Philadelphia website.

Conclusion

In most cases, a dent in the back of the head is a harmless finding related to natural skull asymmetry or a past, forgotten bump. However, being aware of the potential causes and accompanying symptoms is important. If you have any concerns, particularly if the dent appeared suddenly or is associated with other neurological symptoms, don't hesitate to consult a healthcare provider for a professional evaluation.

Frequently Asked Questions

While it's a common fear, a dent in the skull is very rarely a sign of cancer. Cancers that affect the skull are typically aggressive and cause other significant symptoms. Most dents are benign variations, old injuries, or cysts.

For adults, a change in sleeping position is unlikely to cause a permanent dent in the skull, unlike in infants whose skulls are still soft. An adult's skull is fully formed and rigid.

Soft spots, or fontanelles, are normal gaps between the skull bones in infants and are not dents. They are meant to fuse over time. A dent, in contrast, is an indentation in the bone itself.

You should see a doctor if the dent is new, unexplained, growing, or if it's accompanied by other symptoms like persistent headaches, vision changes, or confusion.

Yes, a severe head injury that caused a depressed skull fracture can result in a permanent indentation. However, many minor dents from older injuries might not be remembered.

While severe nutritional deficiencies like rickets can cause bone deformities, a specific dent in the back of the head is not a common symptom. It is far more likely to be related to other causes.

Not necessarily. Many dents are completely external to the brain and don't indicate any underlying brain damage. However, a dent from a severe injury may warrant further investigation to ensure there's no related internal issue.