What Causes Blood Clots in Mouth

Common Causes of Blood Clots in Mouth

The presence of blood in the mouth can be extremely worrying, specifically if it is a spontaneous bleed with no clear etiology.

Bleeding when coughing (hemoptysis), vomiting (hematemesis) or from the nose (epistaxis) suggests the most likely source of the bleed– the respiratory passages, intestinal tract or nasal cavities respectively. Many of the causes of bleeding in these cases may also be responsible for bleeding from the mouth (stomatorrhagia).

In order to recognize the most likely cause, it is essential to take preceding occasions into consideration. Discovering blood in the mouth is expected but nevertheless stressing and potentially severe after these conditions:

  • after dental work
  • postoperatively after surgery to the head or neck (mouth, nose, nasal sinuses, throat, tonsils, throat).
  • after trauma to the head and neck.

Main Causes of Blood Clots in the Mouth

Recurrent bleeding from the mouth, extending over weeks or longer, should always raise the issue about oral cavity cancer. Malignant growths within the nasal cavity, esophagus or larynx might also result in bleeding from the mouth.

Bleeding may seldom be plainly apparent as it might be swallowed along with saliva, or drain pipes down into the esophagus. It might just be obvious upon brushing or spitting and due to the action of gravity, it might be more noticable upon waking after sleeping or lying flat.

Blood that swimming pools in the mouth is a serious sign, usually a sign of a rupture of an artery. It needs instant medical attention.

Mouth Problem

  • Injury to the head or neck.
  • Stomatitis – swelling of the mouth due to mechanical or chemical trauma.
  • Bleeding cavities (tooth cavity), gingivitis, periodontitis.
  • Bleeding aphthous ulcers (mouth sores).
  • Infections – candida albicans, herpes, cytomegalovirus (CMV), viral hemorrhagic fevers.
  • Scurvy (vitamin C deficiency).
  • Heavy metals like lead, mercury or arsenic poisoning.
  • Cancer – mouth, nasal cavity, pharynx.
  • Bleeding disorders like hemophilia.
  • Unusual syndromes like Sackey-Sakati-Aur syndrome and Gardner-Morrisson-Abbot syndrome.

Blood form Nose

This is discussed further under the causes of epistaxis (nosebleeds).

  • Hay fever, post nasal drip.
  • Injury like nose picking, substance abuse (cocaine snorting), use of nasal spray (inhalants).
  • Head injury.
  • Dry air.
  • Infections – sinusitis, rhinitis, vestibulitis.
  • Some of the less typical causes consist of hypertension, Wegener’s granulomatosis.

Blood Clots from Throat

Pharyngitis (swollen throat) might be due to:

  • Infections – tonsillitis (tonsillopharyngitis) or pharyngitis.
  • Chemical injury – consuming destructive compounds, severe GERD (gastroesophageal reflux).
  • Allergic reactions.
  • Abscess (peritonsillar, parapharyngeal, retropharyngeal).
  • Tumors.


This is discussed further under the causes of blood clots in the vomit. Bleeding from lower down in the gut (stomach or duodenum) is more likely to appear dark brown to black, much like coffee grounds. It will only be passed out upon vomiting.

  • Lacerations (Mallory-Weiss tear).
  • Perforation.
  • Tumors – adenocarcinoma, squamous cell carcinoma.
  • Varices.
  • Esophagitis – reflux, contagious, erosive, eosinophilic.
  • Strictures.
  • Ulcers.
  • Barrett esophagus.

Larynx, Trachea, Bronchi and Lungs

This is discussed further under coughing up blood.

  • Trauma.
  • Foreign body.
  • Infections – laryngitis, epiglottitis, bronchitis, pneumonia, tuberculosis.
  • Bronchiectasis.
  • Broncholithiasis.
  • Cancer.
  • Lung abscess.
  • Lung artery rupture.
  • Lung embolism.
  • Sarcoidosis.
  • Aortic aneurysm leaking into the lung cavity.

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A.Muradov (Dental Expert Team)

As a marketing specialist, he pays great attention to health and healthy lifestyle. He is our freelancer in the field of dentistry.

Your Oral Health
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