A canker sore is a common, non-contagious sore that develops on the soft tissues inside the mouth. These small, shallow lesions are painful, making activities like eating and talking uncomfortable. Canker sores typically have a distinct appearance: a white or yellowish center surrounded by a bright red, inflamed border. This article explores the characteristics of these mouth ulcers and explains the circumstances under which they may bleed.
Understanding Canker Sores and Their Appearance
Canker sores are superficial erosions that occur on the delicate mucosal lining of the mouth, commonly forming on the cheeks, lips, tongue, or soft palate. Their characteristic appearance results from the loss of the protective top layer of tissue, exposing the underlying membrane.
The center of the ulcer is covered by a fibrinous membrane, which gives it the pale white or yellow color. This membrane is a collection of dead cells, fibrin, and inflammatory debris, while the surrounding red halo is the result of the inflammatory response in the adjacent healthy tissue.
Why a Canker Sore May Bleed
A typical, uncomplicated canker sore does not bleed spontaneously, but it can bleed easily when subjected to physical force. The pain results from exposed underlying nerve endings. Beneath the ulcer’s surface are tiny blood vessels and capillaries that lack the protection of the mucosal layer.
Bleeding is almost always a result of mechanical trauma to this exposed, delicate tissue. Common causes include accidentally biting the area, aggressive brushing, or friction from rough foods like chips or crusty bread. Dental appliances, such as braces or dentures that rub against the ulcer, can also cause minor bleeding by disrupting the fragile base of the sore.
Distinguishing Minor Bleeding from Serious Symptoms
Minor bleeding from a canker sore is generally expected if the area has been physically disturbed. This bleeding is usually brief, appearing as a faint pink tinge on a toothbrush or a small spot of blood that stops almost immediately. The blood vessels involved are small capillaries, meaning the flow is minimal and self-limiting.
If minor bleeding occurs, gently rinse the mouth with cold water to help restrict the blood vessels. Applying gentle pressure with a clean, moist gauze pad for a few minutes can also aid clotting. Avoid further irritation by sticking to soft, bland foods and using a soft-bristled toothbrush until the sore begins to heal.
More concerning bleeding is that which is unprovoked, persistent, or heavy. Bleeding that continues for a prolonged period despite gentle pressure, or recurs without apparent trauma, should be noted. Sores that are getting larger instead of healing, or those that exhibit unusual color changes, are also signs that require attention. Persistent bleeding can be a symptom of a more extensive underlying issue.
When to Seek Professional Advice
While most canker sores heal naturally within one to two weeks, certain features warrant a consultation with a dentist or physician. If a sore is unusually large or does not show signs of healing after 14 days, professional advice is necessary. Persistent, heavy, or unprovoked bleeding also requires medical evaluation.
Seeking advice is important if the sores are accompanied by systemic symptoms, such as fever, skin rash, diarrhea, headache, or persistent fatigue. In rare instances, persistent, non-healing ulcers or those with unusual bleeding may require a biopsy to rule out more serious conditions, including certain types of oral cancer or systemic diseases. A healthcare professional can accurately diagnose the issue and recommend an appropriate treatment plan.