A crease or indentation on the back of your head is a common observation. While it might seem unusual, these features are often harmless, stemming from typical anatomical structures or everyday factors. Understanding their various reasons can help alleviate concerns.
Natural Anatomical Variations
The human skull is not perfectly smooth. It consists of several bones joined together, and these junctions or bony projections can be felt as ridges or creases. The occipital bone, which forms the lower back part of the skull, features natural landmarks that can be perceived as indentations or bumps.
One such landmark is the external occipital protuberance (EOP), also known as the inion. This bony projection is located centrally on the occipital bone where the neck meets the head. It serves as an attachment point for muscles and ligaments, and its size can vary, sometimes appearing more pronounced, particularly in males.
Another anatomical feature that might be felt as a crease is the lambdoid suture. This dense, fibrous joint connects the occipital bone with the two parietal bones higher up on the skull. While these sutures typically fuse with age, their location can sometimes create a discernible line or subtle depression, especially in individuals with less soft tissue. The nuchal lines, faint bony ridges extending from the EOP, also provide attachment points for neck muscles and can contribute to a crease.
Common Lifestyle and Skin Factors
Beyond bone structure, lifestyle habits and skin characteristics can contribute to creases on the back of the head. Consistent pressure on the head, often from sleeping positions, can influence soft tissue shape. This phenomenon, known as positional molding, is more commonly recognized in infants, but prolonged pressure can also affect adults.
Regularly sleeping on your back can lead to skin and soft tissues conforming to the surface, creating temporary or lasting creases. Pressure and friction against a pillow can also contribute to lines, similar to sleep wrinkles on the face. Changing sleeping positions or using specialized pillows might help reduce these lines.
Skin elasticity changes with aging, and weight fluctuations can lead to skin folds. These changes can result in creases on the scalp, much like those seen elsewhere on the body. In some instances, Cutis Verticis Gyrata (CVG) causes the scalp to thicken and form visible folds or ridges resembling the brain’s surface. CVG can range from slight waves to more pronounced folds and is more common in men.
When to Seek Medical Advice
While a crease on the back of the head is often an anatomical variation or a result of common lifestyle factors, certain signs and symptoms warrant medical consultation. Seek medical advice if the crease is new, rapidly changing in size or appearance, or seems to be growing.
Concerns should also be raised if the crease is accompanied by pain, tenderness, swelling, redness, or warmth, as these could indicate an underlying issue. The presence of neurological symptoms with a head crease also warrants immediate medical evaluation. These can include persistent headaches, changes in vision, dizziness, lightheadedness, or sensations of numbness or tingling.
A crease from a recent head injury or trauma should also be assessed by a doctor, even if initial symptoms seem mild. In most cases, a crease on the back of the head is benign, but knowing when to consult a medical professional is important for peace of mind and to rule out any rare conditions.