Hidden crisis of undiagnosed hypertension among women of reproductive age with elevated blood pressure: a regional disparities and determinants using Tanzania nation survey

Hypertension, the leading risk factor for cardiovascular diseases, remains largely undiagnosed in low-resource settings. This study focuses on the hidden crisis of undiagnosed hypertension among women of reproductive age with elevated blood pressure (BP) in Tanzania, where up to 90% remain unaware of their condition. Using data from the 2022 Tanzania Demographic and Health Survey and Malaria Indicator Survey (TDHS-MIS), this cross-sectional study analyzed a nationally representative sample of 853 women aged 15–49 years with elevated BP. Hypertension was defined as an average systolic blood pressure (SBP) ≥ 140 mmHg, diastolic blood pressure (DBP) ≥ 90 mmHg, or current antihypertensive medication use. Undiagnosed hypertension was categorized based on self-reported lack of prior diagnosis. Multilevel logistic regression was employed to identify determinants at individual and community levels, while forest plots assessed regional disparities. The prevalence of undiagnosed hypertension was 77%. Regional disparities were evident, with the Western (90%) and Central (89%) zones showing the highest prevalence, these zonal estimates are elevated because key regions within them report very high proportions, Tabora (97%) and Dodoma (90.5%) respectively. In contrast, Zanzibar had the lowest prevalence at 48%. With each additional year of age, the odds of being undiagnosed decreased by 8.0% (AOR: 0.92, 95% CI: 0.89–0.95), while married women (AOR: 0.21, 95% CI: 0.08–0.59)women with internet access (AOR: 0.32, 95% CI: 0.15–0.69) and women from wealthier households all had significantly lower odds of undiagnosed hypertension ((middle (AOR: 0.32, 95% CI: 0.16–0.67)) and ((higher socioeconomic classes (AOR: 0.37, 95% CI: 0.17–0.80)). Community-level variation accounted for 25–32% of disparities, with a Median Odds Ratio (MOR) of up to 3.30, indicating substantial contextual influence. The high prevalence of undiagnosed hypertension among Tanzanian women highlights the urgent need for targeted interventions. Improving health awareness, integrating screening into primary care, and addressing regional inequities can significantly reduce this burden and improve maternal and cardiovascular health outcomes.