The human tongue is a complex, muscular organ covered in specialized tissue. Observing an unexpected change, such as a depression, groove, or what appears to be a hole, can understandably cause alarm. These changes are rarely a signal of serious illness and often reflect normal variations in anatomy, temporary irritations, or common benign conditions. Understanding the various causes, which range from inherited structural features to acquired inflammatory lesions, helps distinguish between a harmless anomaly and a change that warrants professional attention.
The Natural Central Groove and Fissured Tongue
A common reason for the appearance of a “hole” is the median lingual sulcus, the natural groove running down the center of the tongue’s upper surface. This anatomical feature divides the tongue into symmetrical halves and can be quite pronounced in some individuals, making it look like a deep fissure. This groove is a normal part of the tongue’s structure, and its depth varies from person to person.
Fissured Tongue, also known as scrotal or plicated tongue, is a benign condition characterized by multiple grooves or furrows on the dorsal surface. These fissures typically vary in depth and may be organized in a central longitudinal furrow with smaller grooves branching out. The condition has a genetic basis and becomes more common and pronounced with age. While usually asymptomatic, these deep grooves can trap food debris and bacteria, which may cause the fissures to appear darker or deeper, thus resembling a series of small holes.
Pits and Lesions Caused by Trauma or Inflammation
Localized depressions can result from acute damage or inflammation rather than structure. Traumatic lesions are caused by mechanical injuries, such as accidentally biting the tongue, friction from a jagged tooth or sharp food, or irritation from dental work. These injuries typically result in a temporary ulcer or pit that heals quickly once the source of irritation is removed. A small, healed piercing site can also be mistaken for a random pit.
A specific type of inflammatory depression is the Aphthous Ulcer, commonly known as a canker sore, which presents as a painful, shallow, round, or oval lesion. Minor aphthous ulcers are small and have a distinct appearance with a yellow-gray center surrounded by a bright red inflammatory halo. These sores are not contagious and often heal spontaneously without scarring within seven to fourteen days. Major aphthous ulcers are larger, deeper, and can take weeks or months to heal, potentially leaving a scar.
Chronic Conditions Altering Surface Texture
Some conditions cause widespread changes to the tongue’s surface texture that a person might interpret as multiple pits or a general breakdown of the tissue. Geographic Tongue, or benign migratory glossitis, involves smooth, red patches that lack the normal surface papillae (tiny projections) and are often surrounded by slightly raised, grayish-white borders. Because the papillae are missing, the patches look smooth and sometimes appear sunken or “pitted,” and these areas characteristically migrate or change location over days or weeks.
Another condition is Median Rhomboid Glossitis (MRG), which appears as a reddish, often diamond- or oval-shaped area in the middle of the tongue’s dorsal surface. This area is smooth because the filiform papillae, which give the tongue its textured appearance, are absent. MRG is often associated with a chronic fungal overgrowth, specifically Candida. Although usually painless, this smooth, depapillated patch can look like a permanent depression or hole in the center of the tongue.
Warning Signs and Seeking Professional Advice
While most tongue changes are benign, certain signs suggest the need for a professional evaluation by a dentist or physician. A lesion or sore that does not show any signs of improvement or heal completely within two weeks should be examined immediately.
Additional warning signs include persistent, unexplained pain or numbness in the tongue. Other symptoms that require attention are a lump or thickening on the tongue or in the neck, difficulty swallowing or moving the tongue, and unexplained bleeding. Although the majority of depressions or pits are harmless, a consultation ensures an accurate diagnosis and rules out any more serious underlying issues.