Dizziness or feeling faint is a normal symptom during pregnancy. It is more common in the first trimester, but you may experience it throughout your pregnancy.
Why do I feel lightheaded, faint, or dizzy during pregnancy?
You might occasionally feel lightheaded or dizzy when you’re pregnant because your cardiovascular system undergoes dramatic changes: Your heart rate goes up, your heart pumps more blood per minute, and the amount of blood in your body increases by 30 to 50 percent.
In most pregnancies, the blood vessels dilate and blood pressure gradually drops, reaching the lowest point in midpregnancy. It then begins to go back up, returning to its regular level by the end of pregnancy. In the second and third trimesters, a growing uterus also puts pressure on veins and slows circulation to the lower half of your body.
Your cardiovascular and nervous systems can usually adjust to these changes and maintain adequate blood flow to your brain. But sometimes they don’t adapt quickly enough, which can leave you feeling lightheaded or dizzy, or even make you faint.
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 yet producing enough blood 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.
The main cause of dizziness in pregnancy is due to the rising hormones that cause your blood vessels to relax and widen. This helps increase the blood flow to your baby, but it slows the return of the blood in the veins to you. This causes your blood pressure to be lower than usual, which can reduce the blood flow to your brain, temporarily causing dizziness.
Dizziness is also caused by low blood sugar levels that may occur as your body adapts to changes in your metabolism. Women who are anemic or who have varicose veins may be more susceptible to dizziness than others. During the second trimester, dizziness may be caused because your& growing uterus puts pressure on blood vessels.
Dizziness may also occur later in your pregnancy if you lie on your back, allowing the weight of the baby to press on your vena cava (a large vein that carries blood from your lower body to your heart).
How can I prevent dizziness when you are pregnant?
You can take steps to minimize dizziness during pregnancy. Here are some common causes of lightheadedness during pregnancy as well as the precautions you can take:
Don’t stand up too fast. When you sit, blood pools in your feet and lower legs. If your body isn’t able to adjust when you stand up, not enough blood returns to your heart from your legs. As a result, your blood pressure drops quickly, which can leave you feeling faint.
To prevent this, avoid springing up from your chair or bed. When you’re lying down, sit up slowly and stay seated for a few minutes with your legs dangling over the side of the bed or couch. Then slowly rise from sitting to standing.
Your blood may also pool in your feet and legs when you stand in one place for a long time. If you’re in a situation where you can’t move around, try shaking your legs to promote circulation.
Wearing support stockings can also help circulation in the lower half of your body.
Don’t lie on your back. In your second and third trimesters, your growing uterus can slow the circulation in your legs by compressing the large vein (inferior vena cava) that returns blood from the lower half of the body to the heart and the pelvic veins. Lying flat on your back can make this problem worse.
About 8 percent of pregnant women in their second or third trimester develop a condition called supine hypotensive syndrome. If you have this condition, it means that when you lie on your back, your heart pumps less blood and your blood pressure drops, so you may feel anxious, lightheaded, and nauseated until you shift position.
To prevent this problem, lie on your side instead of flat on your back. A pillow placed behind you or under your hip can help you stay on your side (or at least tilted enough to keep your uterus from compressing the vena cava).
Eat and drink regularly. When you don’t eat enough, you can end up with low blood sugar (hypoglycemia), which can make you feel dizzy or faint. This can happen much more easily when you’re pregnant. Keep your blood sugar from getting too low by eating small meals frequently during the day instead of three large ones. Carry healthy snacks to eat when you get hungry on the go.
Dehydration can have a similar effect, so stay well hydrated by drinking plenty of water. The Institute of Medicine recommends that pregnant women drink about 10 8-ounce cups of water or other beverages each day. You may need even more if you’re exercising or it’s hot. (If your urine is dark yellow or cloudy, you’re not drinking enough.)
Avoid overheating. Spending time in a hot room or taking a hot bath or shower can make your blood vessels dilate, lowering your blood pressure and making you feel woozy.
If you feel dizzy when you get too hot, avoid stuffy, crowded places and dress in layers so you can shed clothes as necessary. Take warm showers or baths instead of hot ones, and try to keep the bathroom cool.
Don’t overdo it when you exercise. Exercise can sometimes cause you to hyperventilate and feel faint. Although exercise can help your circulation, be careful not to overdo it. Take it easy, and stop if you feel tired or unwell.
What do to do if you feel faint when you are pregnant?
There are a few steps you can follow to help relieve the feeling that you are going to faint. It is common to faint during pregnancy, so be cautious.
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 actually 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. The bottom line is that if dizziness or light headedness are persistent even after you take steps to treat and prevent them, tell your practitioner how you’re feeling at your next visit.