Updated May 16, 2014.

While you don’t need to worry much about many headaches, there is such a thing as dangerous headaches in pregnancy. Migraines won’t necessarily get worse during pregnancy, and they can be treated fairly easily, but occasionally a headache can be a warning sign of more serious problems.

Migraines or other headaches occur during pregnancy for the same reasons they occur in most people -- as a result of fatigue, tension, eyestrain, among other causes.

Changes in hormone levels and body chemistry may play a role in the development of migraines. Conservative treatment measures such as warm compresses and rest can be effective for many women, but medications such as Tylenol (acetaminophen) may be necessary in others. Be sure to learn more about which medications are safe to use during pregnancy.

When to Worry

When a headache during pregnancy is accompanied by dizziness, blurred vision, or blind spots (scotoma) it is time to call your obstetrician or health care provider. These could be signs of preeclampsia, a condition that develops during the second half of pregnancy. It is marked by elevated blood pressure (hypertension), protein in the urine, and swelling, usually in the feet and legs.
Left untreated, preeclampsia can develop into eclampsia which includes seizures. Both conditions are dangerous to the mother’s health and need to be treated urgently. In some cases, the only treatment is delivery of the infant. Be sure to discuss any concerns you may have about headaches or other symptoms with your obstetrician or health care provider.

He will ensure that you are monitored and treated appropriately.

<sub>Source:

Ratcliffe, Stephen, et al, ed. Family Practice Obstetrics, Second Edition. Hanley & Belfus, Inc.: Philadelphia. 2001.</sub>