Headache in the third trimester: what to know

Late-pregnancy headaches can follow dehydration, heat, poor sleep, skipped meals, eye strain, stress, or a viral illness. Nasal congestion from allergic rhinitis or sinus symptoms can add pressure around the face. Headache may also occur with high blood pressure or pre-eclampsia, which can affect the brain, liver, kidneys, and placenta. The headache itself cannot identify the cause, so its timing, severity, associated symptoms, and blood-pressure reading matter.

A headache linked with visual changes, pain below the ribs, sudden swelling of the face or hands, vomiting, or feeling very unwell deserves urgent attention. Do not assume a familiar headache is harmless if it changes during pregnancy.

Rest in a quiet, dim room, drink water regularly, and eat a small balanced snack if you have missed food. Note when the pain began, where it is, how strong it feels, and whether movement, light, or sound changes it. Check your blood pressure if you have been given a monitor and follow your maternity team’s instructions.

Use only medicines approved by your obstetric clinician or pharmacist. Avoid starting anti-inflammatory pain medicines, combination cold remedies, or herbal products without checking first. Arrange same-day advice for a headache that does not settle or keeps returning.

Contact your maternity unit urgently for a severe or sudden headache, a headache that persists despite rest and approved treatment, blurred or flashing vision, confusion, weakness, difficulty speaking, seizure, fainting, fever with a stiff neck, repeated vomiting, breathlessness, chest pain, or pain under the ribs. Seek emergency help if you feel critically unwell. Reduced fetal movement alongside your symptoms also needs immediate maternity guidance.

Ask: Could my blood pressure or urine need checking? Which pain reliever and dose are suitable for me? What symptoms should take me directly to the maternity unit? Could congestion, dehydration, or another illness be contributing?