Headache after vomiting

Vomiting removes fluid and salts and can leave the mouth dry, urine darker, and the head aching. Repeated retching strains the neck and scalp muscles. The original illness may also cause both symptoms: a stomach infection, migraine, medication reaction, or another condition. Fever, cough, sore throat, or body aches may accompany Common Cold or COVID-19, while heat exposure can lead to Heat Exhaustion.

Headache after one episode that improves as you rehydrate is different from a headache that began before vomiting, keeps worsening, or follows a head injury. The symptom combination alone cannot establish its cause.

Rest and take small, frequent sips of water or an oral rehydration drink if you can keep fluids down. Increase the amount gradually, then try bland foods when nausea eases. Avoid alcohol and strenuous activity while recovering. Keep track of further vomiting, fluid intake, urination, fever, pain location, and any new symptoms. A pharmacist can advise about suitable medicines, particularly if you are pregnant or take regular treatment.

Seek emergency help for a sudden severe headache, confusion, fainting, seizure, weakness, trouble speaking, stiff neck with fever, blood or coffee-ground material in vomit, severe abdominal pain, or a recent head injury. Obtain urgent medical advice if you cannot keep fluids down, pass very little urine, feel increasingly drowsy, or have severe dizziness. Arrange review for recurrent vomiting or headaches, or symptoms after travel or possible infection; see Dehydration and Dengue Fever for related information.

How can I replace fluids safely, and could my medicines, migraine, infection, or another condition explain the vomiting and headache? Which signs mean I should seek urgent treatment?