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He should be seen at ER. A doctor would examine him and if needed can call an ENT specialist who are available on call at ER. He may need:
1) Cauterization of the bleeding point.
2) Nasal packing
Avoid nose picking or blowing the nose, as it can dislodge the clot. If he has high blood pressure, that should be controlled. If he is taking aspirin or any related products, may need to stop them for time being.
If there is a low platelet count or any bleeding disorder developing; this may be responsible for the bleeding. These are called as acquired coagulopathies or blood dyscrasias. Among the more common acquired coagulopathies are thrombocytopenia and liver disease. Following are the other causes;
2) Hereditary hemorrhagic telangiectasia; this is recurrent bleeding from vascular anomalies.
3) Idiopathic causes: About 10% of people with nose bleed (epistaxis) have no identifiable causes.
5) bacterial or viral infection
6) Nasal septal abnormality.
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