What causes apparently spontaneous nosebleeds

Epistaxis - Causes and Risks

Nosebleeds occur when the fine vessels in the highly perfused nasal mucosa are injured. In the front part of the nose, the so-called Locus Kießelbachi, several blood vessels meet, which is why most of the bleeding occurs here (90%). Bleeding in the front part of the nose is almost always harmless. Dangerous bleeding is more common in the back of the nose.

The causes are either local, i.e. they are in the area of ​​the nose and paranasal sinuses, or are systemic, e.g. as a symptom of an illness or as a side effect of taking medication or a phase of physical development.

Local causes of nosebleeds

Often, a strong blowing of the nose or nose picking is enough to tear the sensitive vessels of the nose and thereby trigger nosebleeds. This is favored by a previously damaged nasal mucous membrane: Overheated rooms in winter, air conditioning in summer or allergies such as hay fever cause dry, irritated mucous membranes. Decongestant nasal drops or sprays should only be used briefly for the sake of the nasal mucous membranes. If the mucous membrane is badly damaged, bleeding can appear for no reason whatsoever.

Nosebleeds can also be triggered by external influences, such as a blow or a fall - regardless of whether the nasal bone or the nasal septum is broken or there is no fracture. If small children stick a foreign body (e.g. a peanut, a pea, a pearl or a small button) into a nostril, this can also cause nosebleeds due to an injury to the nasal mucosa.

Changes to the nasal septum, such as accumulations of pus (abscess) or small tears or holes in the septum (perforation), can also lead to bleeding of varying degrees. In rare cases, repeated nosebleeds should be thought of as benign or malignant tumors (neoplasias) in the nasal cavity or in the paranasal sinuses.

Systemic causes of nosebleeds

Epistaxis as a symptom of a disease

Nosebleeds can sometimes appear as an accompanying symptom or harbinger of a serious illness. Therefore, if you have frequent, unexplained bleeding, you should consult your ENT doctor.

The so-called systemic triggers for nosebleeds include above all kidney and vascular diseases such as high blood pressure (hypertension) and arteriosclerosis. But even with febrile infections such as flu or measles there is an increased blood flow to the mucous membranes and thus possibly more frequent bleeding. This also applies if the nasal mucous membrane is inflamed as a result of colds and allergies.

Patients with hemophilia, leukemia, a congenital dysfunction of the blood platelets (thrombopathy) or the rare hereditary vascular disease Osler's disease are also prone to nosebleeds.

Nosebleeds from medication

Medicines that inhibit blood clotting in the body, so-called anticoagulants, are also known colloquially as blood thinners. They lead to an increased tendency to bleed and thus more often to nosebleeds. These include, for example, acetylsalicylic acid (ASA) and the active ingredient group of coumarins or coumarins, which specifically lower the level of vitamin K in the body, which is required for blood clotting.

Epistaxis in children and adolescents

In children and adolescents, bleeding often occurs in the front part of the nose even without external influence. This is usually completely harmless. In children and adolescents, this often happens in the course of strong growth spurts, e.g. during puberty.

Nosebleeds during pregnancy

During pregnancy, all mucous membranes are supplied with more blood, so it is easier for nosebleeds to occur. It is completely harmless.