Differential Diagnosis for a Pregnant Patient with Lightheadedness

Single Most Likely Diagnosis

• Physiological changes of pregnancy: Lightheadedness or dizziness is a common symptom in pregnancy, particularly during the first trimester, due to physiological changes such as vasodilation and decreased blood pressure.

Other Likely Diagnoses

• Anemia: Common in pregnancy due to increased blood volume and demand for iron, leading to reduced hemoglobin levels and potentially causing lightheadedness.
• Dehydration: Pregnant women may experience dehydration due to increased fluid demands, leading to symptoms like lightheadedness.
• Hypoglycemia: Low blood sugar can occur in pregnancy, especially if the woman has gestational diabetes or is fasting, leading to feelings of lightheadedness.

Do Not Miss Diagnoses

• Preeclampsia: A condition characterized by high blood pressure and often protein in the urine, which can lead to severe complications if not promptly treated. While less common, it's critical to rule out due to its potential severity.
• Placenta previa: A condition where the placenta covers the cervix, which can cause bleeding and lead to lightheadedness due to blood loss.
• Eclampsia: The onset of seizures in a woman with preeclampsia, which is a medical emergency.

Rare Diagnoses

• Cardiac conditions: Pre-existing heart conditions or those that develop during pregnancy, such as peripartum cardiomyopathy, can cause lightheadedness due to decreased cardiac output.
• Neurological disorders: Conditions like multiple sclerosis or peripheral neuropathy can cause dizziness or lightheadedness, though these are less directly related to pregnancy itself.
• Hyperthyroidism: An overactive thyroid gland can lead to symptoms including lightheadedness, though this is less common in the context of pregnancy-related dizziness.