Yes, a persistent or severe headache can be a warning sign of preeclampsia, especially if it is stronger than a normal pregnancy headache and does not improve with rest, hydration, or mild pain relief. Normal pregnancy headaches are usually mild and related to stress, hormones, or dehydration, while preeclampsia headaches are often more intense and ongoing. Other key symptoms to watch for include high blood pressure, sudden swelling in the face or hands, blurred vision or flashing lights, and upper abdominal pain. A pregnant woman should seek immediate medical care if she experiences a severe or unusual headache along with any of these warning signs, as it may indicate a serious condition affecting both mother and baby.