Fainting and a nose bleed: what to know

A nose bleed can be frightening and may trigger a reflex fall in blood pressure, particularly with pain, heat, or prolonged standing. Swallowed blood can cause nausea. Heavy or persistent bleeding may contribute to weakness, while dehydration, anaemia, hypoglycaemia, or an irregular rhythm such as Atrial Fibrillation may produce faintness independently. The nose bleed does not prove why someone blacked out, and the event should be judged by its severity and recovery.

Sit upright, lean slightly forward, and pinch the soft part of the nose continuously. Breathe through the mouth and spit out blood rather than tipping the head back. After the bleeding settles, rest and rise gradually. If the person becomes faint, help them lie flat and protect them from injury. Do not put tissue deep inside the nose or give food and drink while they are unconscious or confused. Record medicines, injury, heat exposure, and the time to recovery.

Call emergency services if bleeding is heavy, follows a significant head injury, causes breathing difficulty, or does not stop with firm pressure, or if the person remains unconscious, has abnormal breathing, chest pain, severe breathlessness, new weakness, or ongoing confusion. Arrange prompt review after a first blackout, repeated fainting, or bleeding that keeps returning. Blood-thinning medicine increases the need for timely advice.

Ask whether medicines, nasal dryness, blood pressure, anaemia, or another condition could be contributing; whether blood tests are needed; and how to prevent further nose bleeds. Describe the amount and duration of bleeding and any warning symptoms before fainting.