Dizziness & Headache at 38 Weeks Pregnant: Causes & When to Act

Common Causes in Late Pregnancy

At 38 weeks, your body is under maximum cardiovascular and metabolic demand. Dizziness and headaches can stem from normal adaptations or signal complications needing prompt evaluation.

1. Normal Physiological Changes

• Increased blood volume + progesterone-induced vasodilation → lower blood pressure.
• Uterus compresses inferior vena cava when supine → reduced venous return.
• Hormonal fluctuations affect vascular tone.

2. Dehydration

Frequent urination, nausea, or simply not drinking enough → reduced intravascular volume → dizziness, headache.

3. Low Blood Sugar (Hypoglycemia)

Long gaps between meals; pregnancy increases metabolic rate. Eat small, frequent meals with protein + complex carbs.

4. Iron-Deficiency Anemia

Expanded blood volume dilutes red cells. Fatigue, pallor, shortness of breath, dizziness. Check ferritin/CBC.

5. Postural (Orthostatic) Hypotension

Standing up too fast → blood pools in legs → transient brain hypoperfusion. Rise slowly; sit on bed edge first.

⚠️ Red Flags: Seek Care Immediately

• Severe/persistent headache unrelieved by rest, hydration, acetaminophen.
• Visual changes: blurring, spots, flashing lights (scotomata).
• Upper abdominal pain (especially right side).
• Sudden swelling of face, hands, feet.
• Nausea/vomiting new in late pregnancy.
• Blood pressure ≥140/90 mmHg (preeclampsia threshold).

These suggest preeclampsia—a serious hypertensive disorder requiring urgent management to protect you and baby.

What to Do Now

1. Sit/lie on left side; drink water; eat a snack.
2. Check blood pressure if you have a home cuff.
3. Call your OB/midwife today to report symptoms.
4. If red flags present, go to L&D or ER immediately.

Bottom Line

While often benign, new or worsening dizziness/headache at term deserves professional assessment to rule out preeclampsia and other treatable conditions.