Emergency department blood pressure elevations frequently occur without documented hypertension diagnosis

BACKGROUND: High blood pressure readings (HBPRs) are common in emergency department (ED) patients, but the frequency of HBPRs among patients without a documented diagnosis of hypertension (DDxHTN) is unclear. METHODS: We performed a retrospective study of discharged ED encounters at a large Midwestern academic ED in 2024. HBPRs were defined as blood pressure ≥130 mmHg systolic or ≥80 mmHg diastolic. RESULTS: Among 66 624 discharged encounters with blood pressure data, 52 461 (78.7%) had at least one HBPR and 38 715 (58.1%) had at least one Stage 2-range HBPR (≥140/90 mmHg). Among patients with Stage 2-range HBPRs, 22 471 (58.0%) lacked DDxHTN. Older age, female sex, Black race, absence of interpreter need, and Medicare or Medicaid coverage were independently associated with DDxHTN. CONCLUSIONS: More than half of discharged ED patients with Stage 2-range HBPRs lacked DDxHTN, and many had only a single documented blood pressure. The ED may provide an opportunity for blood pressure reassessment and outpatient referral.