Fainting and vomiting at the same time: what to do

A sudden pain, fright, heat exposure, or gut upset can trigger nausea and a reflex fall in blood pressure. Vomiting can then worsen dehydration, making another faint more likely. Low blood sugar may bring sweating, trembling, and confusion. Anaemia, an abnormal heart rhythm such as atrial fibrillation, medication effects, infection, pregnancy, or internal bleeding are other possibilities. The combination cannot be diagnosed from symptoms alone.

If the person is drowsy or still vomiting, roll them onto their side and clear visible material from the mouth. If they are unresponsive, check breathing and call emergency services; begin resuscitation if trained and directed. Keep them still, cool, and supervised. Once fully awake with normal swallowing, offer small sips of oral fluid. Do not give anything by mouth to an unconscious person or make them stand suddenly.

Get emergency help for blood or coffee-ground material in vomit, severe abdominal or chest pain, a head injury, breathing difficulty, new weakness, prolonged confusion, an irregular pounding heartbeat, or another collapse. Urgent review is also needed when vomiting continues, fluids cannot stay down, the faint happened during exercise, or the episode was the first without an obvious trigger.

Note the order of events, food and fluid intake, fever, pain, medicines, pregnancy possibility, urine output, and recovery time. Ask whether blood pressure, blood sugar, blood count, and heart rhythm need assessment.