Blood in the Mouth – Causes of Bleeding from the Mouth

The presence of blood in the mouth can be extremely worrying, especially if it is a spontaneous bleed with no clear etiology. Bleeding when coughing (hemoptysis), vomiting (hematemesis) or from the nose (epistaxis) indicates the most likely source of the bleed – the respiratory passages, gastrointestinal 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 identify the most likely cause, it is important to take preceding events into consideration. Finding blood in the mouth is expected but nevertheless worrying and possibly serious after these conditions :

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

However, the sign of bleeding from the mouth in a situation where none of these events have previously occurred needs to be investigated further in order to quickly and accurately identify the site of the bleed. It is also important to identify whether the blood in the mouth was related to coughing, vomiting or a nosebleed.

Causes of Blood in the Mouth

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

Bleeding may not often be clearly evident as it may be swallowed along with saliva, or drain down into the esophagus. It may only be obvious upon brushing or spitting and due to the action of gravity, it may be more pronounced upon waking after sleeping or lying flat.

Blood that pools in the mouth is a serious sign, most often indicative of a rupture of an artery. It needs immediate medical attention.


  • Injury to the head or neck
  • Stomatitis – inflammation of the mouth due to mechanical or chemical trauma.
  • Bleeding dental caries (tooth cavity), gingivitis, periodontitis
  • Bleeding aphthous ulcers (mouth sores)
  • Infections – candida, 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
  • Rare syndromes like Sackey-Sakati-Aur syndrome and Gardner-Morrisson-Abbot syndrome


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

  • Allergic rhinitis, post nasal drip
  • Injury like nose picking, drug use (cocaine snorting), use of nasal spray (inhalants)
  • Head trauma
  • Dry air
  • Infections – sinusitis, rhinitis, vestibulitis
  • Some of the less common causes include hypertension, Wegener’s granulomatosis


Pharyngitis (inflamed throat) may be due to :

  • Infections – tonsillitis (tonsillopharyngitis) or pharyngitis
  • Chemical trauma – consuming corrosive substances, severe GERD (gastroesophageal reflux)
  • Allergies
  • Abscess (peritonsillar, parapharyngeal, retropharyngeal)
  • Tumors


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

  • Lacerations (Mallory-Weiss tear)
  • Perforation
  • Tumors – adenocarcinoma, squamous cell carcinoma
  • Varices
  • Esophagitis – reflux, infectious, 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
  • Pulmonary artery rupture
  • Pulmonary embolism
  • Sarcoidosis
  • Aortic aneurysm leaking into the pulmonary cavity


  1. Bleeding from the Mouth. Wrong Diagnosis

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  • b.shalini

    my father is suffering from mouth bleeding last 2 months .mouth bleeding is raerly, is it serious problem?

  • Dr. Chris

    Hi B.Shalini

    Yes, it could be a serious problem depending on the cause. Some of the very serious causes include cancer of the oral cavity or throat. Your father needs to be assessed by a doctor to identify the cause of the bleed.

  • b.shalini

    sir, my father mouth bleeding quantity is very less , if it cause is oral cavity or throat cancer is there any problem for life or he can survive with treatment?

  • Dr. Chris

    Hi B.Shalini

    There is no way we can answer that conclusively without knowing his case details. Only your doctor can advise you further. Don’t be misled by the small quantity of blood. If it is cancer, then treatment can either totally resolve the problem or may increase survival rate but this is dependent on a number of factors. Without treatment, chances of survival are very low. Speak to a doctor immediately.