Oral bruising, medically known as an oral hematoma, occurs when blood vessels beneath the moist lining of the mouth rupture. This causes blood to leak and pool into the surrounding soft tissues, creating a noticeable discoloration. Because the mucous membrane is thinner and more vascular than skin, this collection of blood often appears a darker, more intense purple or black color.
Common Causes of Bruising in the Mouth
The most frequent reason for developing an oral bruise is localized physical trauma to the delicate tissues of the cheeks, lips, or palate. Accidental cheek or lip biting is a common culprit, often happening suddenly during chewing or speaking. Impact injuries, such as those sustained from a fall, a blow to the face, or during contact sports, can also rupture capillaries within the mouth.
Dental procedures frequently cause temporary bruising due to the necessary physical manipulation of tissues. Injections of local anesthetic can sometimes nick a small blood vessel, leading to a hematoma at the injection site, often on the palate or back of the mouth. Aggressive flossing or brushing, especially with hard-bristled toothbrushes, may also induce minor bruising on the gums.
Beyond direct injury, certain systemic factors can make a person more prone to easy or spontaneous oral bruising. Individuals taking blood-thinning medications, such as aspirin or prescription anticoagulants, may experience bruising more readily because their blood takes longer to clot. Underlying medical conditions affecting blood clotting or platelet count, like thrombocytopenia or certain liver diseases, can also lead to unexplained bruising throughout the body, including the mouth.
What Oral Bruises Look Like and How They Heal
An oral bruise typically starts as a reddish-purple patch immediately following the injury, quickly deepening to a dark blue, black, or brownish hue. Unlike a flat skin bruise, a significant oral hematoma may feel slightly raised or lumpy as blood pools beneath the surface. Small, pinpoint bruises, known as petechiae, might also appear, particularly on the soft palate.
The healing process for a simple oral bruise is often faster than one on the skin due to the mouth’s high vascularity and rapid cellular turnover. Most minor hematomas begin to fade and resolve naturally within five to ten days. As the body reabsorbs the pooled blood, the color changes, shifting from dark purple to a lighter brown or yellowish shade before disappearing.
Immediate home care can help manage swelling and discomfort following a known injury. Applying a cold compress externally or using ice chips internally can help constrict blood vessels and limit the size of the initial bruise. While healing, avoid sharp, hot, or highly spicy foods that might irritate the surface. Gentle rinsing with a warm saltwater solution can also promote cleanliness and comfort.
Warning Signs Requiring Medical Consultation
While most oral bruises are harmless and self-resolving, certain signs warrant prompt medical attention from a dentist or physician. Bruising that appears frequently without a clear cause (spontaneous bruising) could indicate an underlying disorder related to blood clotting or vessel integrity. A bruise that is extremely large, rapidly expanding, or accompanied by a significant, persistent lump should also be evaluated to rule out a more serious complication.
Seeking professional help is necessary if the bruise does not show signs of improvement or resolution after two weeks, which may suggest a persistent issue or misdiagnosis. Immediate consultation is required if oral bruising is accompanied by systemic symptoms, such as:
- Unexplained nosebleeds
- Bleeding gums
- Excessive fatigue
- Difficulty swallowing or breathing
These combined symptoms may point toward a systemic medical condition requiring urgent diagnosis and treatment.