A nosebleed, also known as epistaxis, is bleeding from the nose. Blood can flow down into the stomach, and cause nausea and vomiting. In more severe cases, blood may come out of both nostrils. Rarely, bleeding may be so significant that low blood pressure occurs. Blood may also come up the nasolacrimal duct and out from the eye.Risk factors include trauma, including putting the finger in the nose, blood thinners, high blood pressure, alcoholism, seasonal allergies, dry weather, and inhaled corticosteroids. There are two types: anterior, which is more common; and posterior, which is less common but more serious. Anterior nosebleeds generally occur from Kiesselbachs plexus while posterior bleeds generally occur from the sphenopalatine artery. The diagnosis is by direct observation.Prevention may include the use of petroleum jelly in the nose. Initially, treatment is generally the application of pressure for at least five minutes over the lower half of the nose. If this is not sufficient, nasal packing may be used. Tranexamic acid may also be helpful. If bleeding episodes continue, endoscopy is recommended.About 60% of people have a nosebleed at some point in their life. About 10% of nosebleeds are serious. Nosebleeds are rarely fatal, accounting for only 4 of the 2.4 million deaths in the U.S. in 1999. Nosebleeds most commonly affect those younger than 10 and older than 50. Cause
Nosebleeds can occur due to a variety of reasons.
Some of the most common causes include trauma from nose picking, blunt trauma (such as a motor vehicle accident), or insertion of a foreign object (more likely in children). Relative humidity (including centrally heated buildings), respiratory tract infections, chronic sinusitis, rhinitis or environmental irritants can cause inflammation and thinning of the tissue in the nose, leading to a greater likelihood of bleeding from the nose.Most causes of nose bleeding are self-limiting and do not require medical attention. However, if nosebleeds are recurrent or do not respond to home therapies, an underlying cause may need to be investigated. Some rarer causes are listed below:Coagulopathy

Thrombocytopenia (thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura)
Von Willebrands disease
Hemophilia
Leukemia
HIV
Chronic liver disease—cirrhosis causes deficiency of factor II, VII, IX,& XDietary

Sulfur dioxide (sulphur dioxide) E220 (as a food preservative used particularly in wines, dried fruits, etc. ) Sulphites as food preservatives
Salicylates naturally occurring in some fruits and vegetablesInflammatory

Granulomatosis with polyangiitis
Systemic lupus erythematosusMedications/Drugs

Anticoagulation (warfarin, heparin, aspirin, etc.) Insufflated drugs (particularly cocaine)
Nasal sprays (particularly prolonged or improper use of nasal steroids)Neoplastic

Squamous cell carcinoma
Adenoid cystic carcinoma
Melanoma
Nasopharyngeal carcinoma
Nasopharyngeal angiofibroma
Nosebleeds can be a sign of cancer in the sinus area, which is rare, or tumors starting at the base of the brain, such as meningioma. Due to the sensitive location, nosebleeds caused by tumors are typically associated with other symptoms, such as hearing or vision problems.Traumatic

Anatomical deformities (e.g.