Dizziness is normal during the first trimester, and can be caused by factors like hormonal changes, morning sickness, iron deficiency and dehydration. Often, fixes can be as simple as drinking more water, standing up slowly, taking iron supplements or getting the rest you need. That said, if you’re feeling dizzy during your second or third trimesters (or pass out or faint during any stage of your pregnancy), make an appointment with your medical provider. To be safe, you’ll want to rule out serious issues, like preeclampsia, pulmonary embolisms (blood clots blocking the arteries leading to the lungs) or peripartum cardiomyopathy (a heart muscle disease).