Nausea and vomiting are common complaints during pregnancy. Their severity and persistence can lead to the diagnosis of hyperemesis gravidarum, which is associated with weight loss, ketonuria, and decreased fetal birth weight. Hypercalcemia in pregnancy can confound these common gastrointestinal symptoms as well as have its own intrinsic maternal-fetal risks. A 23-year-old woman was diagnosed with primary hyperparathyroidism after multiple visits to the emergency department and the obstetrical clinic with symptoms of nausea and vomiting. Her symptoms were initially attributed to hyperemesis gravidarum and only after multiple hospital visits was her hypercalcemia discovered. Her workup led to the diagnosis of primary hyperparathyroidism caused by a solitary parathyroid adenoma. The patient was treated conservatively with intravenous fluids and eventually surgical resection of the parathyroid adenoma which led to complete resolution of her symptoms. This case demonstrates the diagnostic and therapeutic challenges associated with hyperparathyroidism in pregnancy.