Dizziness & Lightheadedness

What It Is & Why It Happens

Dizziness and lightheadedness are frequent cardiovascular symptoms during pregnancy, affecting more than 75% of pregnant individuals at some point.

The primary cause is the rapid expansion of the cardiovascular system. To support the fetus, your blood volume increases by 50%, and your heart works harder. At the same time, elevated levels of progesterone relax the walls of your blood vessels. This vasodilation causes your blood pressure to drop, particularly in the first and second trimesters.

When you stand up, blood pools in your lower limbs, temporarily reducing circulation to the brain (postural hypotension). In later pregnancy, physical pressure from the uterus on the inferior vena cava when lying flat also triggers supine hypotensive syndrome. Other causes include low blood sugar from increased metabolic demands, dehydration, and mild anemia.

Typical Timeline

Dizziness can occur throughout pregnancy, but its triggers vary by trimester:

• First Trimester (Weeks 4-12): Common. Driven by early hormonal surges, blood vessel dilation, and drops in blood sugar or morning sickness-related dehydration.
• Second Trimester (Weeks 13-27): Often peaks as the expanding circulatory system is at its lowest blood pressure point.
• Third Trimester (Weeks 28-40): Frequently triggered by lying on your back, physical compression of major blood vessels, or prolonged standing in hot weather.

Safe Comfort Measures

You can safely prevent and manage dizziness with these lifestyle strategies:

• Stand Up Slowly: When rising from bed or a chair, sit on the edge for a few moments first, then stand up gradually.
• Avoid Lying on Your Back: Sleep and rest on your side (preferably the left side) to remove weight from the inferior vena cava and optimize blood flow.
• Eat Regular Meals: Consume small, frequent meals containing protein and complex carbohydrates every 2 to 3 hours to maintain stable blood sugar levels.
• Stay Hydrated: Drink 8 to 10 glasses of water daily. Dehydration directly lowers blood volume and blood pressure, triggering dizziness.
• Avoid Prolonged Standing: If you must stand for long periods, move your feet and pump your calf muscles to keep blood flowing back to your heart. Wear compression stockings.
• Cool Down: Avoid hot environments, hot showers, or stuffy rooms, which cause further blood vessel dilation.

When to Call the Doctor (Red Flags)

While mild lightheadedness is expected, fainting or dizziness accompanied by neurological symptoms require immediate medical attention.

Contact your healthcare provider immediately or go to the nearest emergency room if you experience:

• Fainting (loss of consciousness) or feeling like you are about to pass out frequently.
• Dizziness accompanied by a severe, persistent headache, visual changes (blurry vision, spots, flashing lights), or sudden swelling (signs of preeclampsia).
• Chest pain, shortness of breath, a rapid or pounding heartbeat (palpitations).
• Dizziness accompanied by severe abdominal pain, vaginal bleeding, or cramping.
• Severe dizziness that persists even after lying down, hydrating, and eating.
• Dizziness accompanied by numbness, tingling, or weakness on one side of your body.