Severe headache in pregnancy during the third trimester

Late pregnancy headache may follow heat, dehydration, poor sleep, hunger, congestion, a viral illness, or muscle tension. Clinicians also consider blood pressure disorders of pregnancy, especially if headache occurs with vision changes, swelling, upper abdominal pain, or vomiting. There is no safe way to identify the cause from pain intensity alone, so an assessment may include blood pressure, urine, examination, and pregnancy monitoring.

Pause activity, move to a cool quiet setting, and take fluids in small amounts. Write down when the pain started, its location and character, and any changes in vision, movement, fever, or nausea. Check with your obstetric team before using medicine, even if it helped before. Call your maternity service today rather than waiting for a routine appointment when pain is severe or ongoing.

Use emergency services for sudden explosive pain, fainting, confusion, seizure, weakness, speech difficulty, severe breathlessness, or new visual loss. Seek urgent maternity assessment for flashing lights, major swelling, pain under the ribs, persistent vomiting, or reduced fetal movement. If you feel faint or your vision is affected, have someone stay with you.

Ask whether you need a same-day blood pressure review, which warning signs mean immediate assessment, and which treatments are appropriate for your pregnancy and current medicines.