Throughout your pregnancy, you may experience a disorienting feeling of unsteadiness or vertigo that can make you feel as if you're about to fall or faint. But don't worry, it's a normal and fairly common symptom of pregnancy that you can, for the most part, avoid by taking a few smart steps.

When does dizziness generally start during pregnancy?

Many women experience dizziness starting between week 12 and the first few weeks of the second trimester of pregnancy.

Is dizziness a common early sign of pregnancy?

Dizziness is not usually one of the first signs of pregnancy, but it can be an early pregnancy symptom if you have low blood sugar due to a case of morning sickness.[1]

You may feel dizzy as a sign of pregnancy even before a missed period if you're not eating much because you're feeling nauseous, which can sometimes (but not always) occur within days of conception.

What causes dizziness during pregnancy?

Early in pregnancy, your body is gearing up to meet the needs of two bodies instead of one. Dizziness is likely due to several factors:

  • Your body isn't producing enough blood yet to fill a rapidly expanding circulatory system.
  • High levels of progesterone can also make your blood vessels relax and widen, increasing blood flow to your baby but slowing it down to you — which can reduce your blood pressure. This, in turn, cuts back on blood flow to your brain, sometimes making your head spin. 
  • Your growing uterus can put pressure on your blood vessels, especially when you're lying on your back.
  • It's not called a bun in the oven for nothing: Your body is generating plenty of heat right now, which means spending too much time in a hot or stuffy room can contribute to feelings of lightheadedness.
  • If your blood sugar drops or you become dehydrated, you're more likely to experience a dizzy spell.

What can I do about dizziness when I'm pregnant?

Keep in mind that no matter how "normal" dizziness is, you shouldn't ignore it. So use common sense: no driving, working out or handling anything that could potentially cause you harm. If you need help, don't be shy about asking.

To stop a dizzy spell, lie down as soon as you start to feel lightheaded so you don't fall or pass out, then elevate your feet to increase blood flow to your brain.

If that's not possible, sit down and bend as far forward as you're able to, putting your head between your knees if you can, and breathe slowly and deeply. If there's no place to lie down or sit, kneel on one knee and bend forward as if you were tying your shoe until the spell passes.

Can I prevent dizziness during pregnancy?

To keep dizziness from starting in the first place:

  • Go slowly. Don't get up too quickly when you're sitting or lying down, since it can cause your blood pressure to drop, triggering dizziness.
  • Make the most of the munchies. Make sure you're eating a healthy, well-rounded diet during pregnancy, with a mix of protein and complex carbs (like whole grain bread or pasta) at every meal to maintain stable blood sugar levels.
  • Feast frequently. Chow down on several small meals throughout the day to prevent dips in your blood sugar, and carry healthy pregnancy snacks with you for a quick blood sugar boost. Good options: a mini-box of raisins, a piece of fruit or some whole wheat crackers.
  • Fill up on fluids. Make sure you're drinking enough water, since dizziness can be a sign of dehydration, too.[2] Aim for around 12 to 13 glasses of fluids a day, and more if it's hot or you're working out.
  • Dress smart. Wear easy-to-shed layers in case you start feeling overheated, and avoid wearing tight-fitting clothes, scarves or hats.
  • Don't lie on your back. In your second and third trimesters, it's best to avoid sleeping on your back, as your growing uterus can press on the vena cava (the main vein that carries blood back to the heart from your lower body region). That can interfere with optimum circulation and cause a feeling of dizziness.
  • Get some fresh air. Spending too much time in a stuffy, overheated indoor space (like a crammed bus, office or store) can trigger dizziness, so as long as you're not feeling overly faint, try to take a five-minute walk outside every hour or so — which can help relieve other pregnancy symptoms like constipation and swelling, too.

When does dizziness during pregnancy usually end?

Once they start, dizzy spells can often last through the rest of your pregnancy. But they should subside after your baby is born.

When should I call the doctor about dizziness during pregnancy?

Sometimes iron deficiency (anemia) can result in fainting spells as oxygen-carrying blood cells are depleted. So if you do pass out, call your doctor ASAP.

Some women might wonder whether dizziness is a symptom of miscarriage. Not to worry: Lightheadedness is not a common sign of miscarriage.

Others may have questions about whether dizziness might be a symptom of preeclampsia. But there's no reason to be concerned there, either. Feeling faint is not a common sign of preeclampsia, which is characterized by the sudden onset of high blood pressure during pregnancy, while dizziness is often caused by the opposite problem: low blood pressure.[3]

The bottom line is that if dizziness or lightheadedness are persistent even after you take steps to treat and prevent it, tell your practitioner how you're feeling at your next visit.