Unmasking the contemporary burden of hypertension in Lagos, Nigeria: insights from an opportunistic screening

Abstract

Background

Hypertension remains the leading modifiable risk factor for global morbidity and mortality, disproportionately affecting low- and middle-income countries (LMICs). In Nigeria, prevalence and control rates remain poor, yet contemporary city-level data are limited.

Objectives

To determine the prevalence, awareness, treatment, and control of hypertension among adults screened during a community-based blood pressure screening campaign in Lagos, Nigeria, in 2023.

Methods

We conducted a cross-sectional opportunistic screening of adults aged ≥18 years across hospitals, pharmacies, workplaces, and public spaces in Lagos, Nigeria. Sociodemographic data, medical history, and lifestyle factors were obtained using a study proforma adapted from the WHO STEPS questionnaire as relevant to our study proforma. Blood pressure (BP) was measured three times with an OMRON M7 Intelli IT device; the mean of the readings defined BP status. Hypertension was classified as systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg, or self-reported use of antihypertensive medication. Descriptive statistics, chi-square tests, and logistic regression analyses were used to identify predictors of blood pressure status.

Results

A total of 1,547 individuals were screened (median age 47 years, IQR 38–57; 51.2% female). Overall hypertension prevalence was 52.5%, comprising 34.7% previously diagnosed and 17.8% newly detected cases. Among hypertensives, 39.9% reported treatment use, and 60.2% of those on medication achieved BP control. Awareness of hypertension was low (34.7%), with significant age and sex disparities: prevalence increased with age, and men were more frequently affected than women (p=0.015). Logistic regression identified age, male sex, higher BMI, low education, and prior diagnosis as significant predictors of elevated BP.

Conclusions

Opportunistic community-based screening in 2023 revealed a high burden of undiagnosed hypertension and suboptimal awareness in Lagos, Nigeria. These findings underscore the need for sustained mass screening, improved access to affordable antihypertensive therapy, and health system strategies to close the care cascade gap. These findings provide novel, contemporary evidence of hypertension burden and care gaps in Lagos, Nigeria, complementing national estimates and offering insights relevant to urban health strategies in low- and middle-income countries.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-026-26310-x.

Introduction

Hypertension is a major non-communicable disease and a leading cause of global morbidity and mortality. In 2023, the World Health Organization (WHO) reported that approximately 1.3 billion adults aged 30–70 years were living with hypertension, corresponding to a global prevalence of about 33% [1]. Nearly three-quarters of this burden occurs in low- and middle-income countries (LMICs) [1].

Worldwide, hypertension represents a “tip of the iceberg” phenomenon, with large proportions of cases undiagnosed, untreated, or poorly controlled. According to WHO estimates, although one-third of adults aged 30–70 years have hypertension, only 54% are diagnosed, 42% receive treatment, and just 21% achieve blood pressure control [1]. These metrics are even worse in LMICs and this is driven by the convergence of rapid urbanization, westernization of lifestyles and weak health systems [1–3]. Hypertension is also a major but preventable risk factor for stroke, heart failure, coronary artery disease, chronic kidney disease, atrial fibrillation, and dementia [4]. It is the single most important contributor to premature death worldwide, accounting for an estimated 10.8 million avoidable deaths annually and 235 million disability-adjusted life years (DALYs) lost or lived with disability [5]. In sub-Saharan Africa (SSA), the prevalence of hypertension has increased, reaching 48% (CI. 42–54%) in women and 34% (CI. 29–39%) in men in 2019 and this burden is characterized by dismally low awareness, treatment and control [1–3].

In Nigeria, the burden of hypertension is high. A 2017 national survey reported a prevalence of 38.1%, with low awareness, poor treatment uptake, and poor control rates [6]. A 2021 meta-analysis confirmed these findings, underscoring the magnitude of the problem [7]. Hypertension is typically asymptomatic, and diagnosis relies on screening. Opportunistic screening has been shown to be effective, cost-efficient, and pragmatic for improving awareness, diagnosis, treatment, and control, particularly in low-resource settings [8–11]. To highlight the importance of early detection, the International Society of Hypertension launched the May Measurement Month (MMM) campaign in 2017. Since its inception, MMM has drawn global attention to undiagnosed and undertreated hypertension, especially in LMICs [12–18].

Lagos, Nigeria’s economic capital and a cosmopolitan city of over 20 million people, is located in the southwest region of the country. The prevalence of hypertension in southwest Nigeria is reported to be as high as 42.1% [6] while Lagos specifically has an estimated prevalence of 27.5% [19] as at 2017, and this is reflected in the high frequency of cardiovascular disease admissions and deaths in the city [20, 21]. With increasing population we hypothesized that the burden of hypertension could have risen over the years. Hence the need for a more contemporary data. The present study reports findings from a community-based blood pressure screening campaign conducted in Lagos, Nigeria, in 2023. Our primary outcomes were the prevalence of hypertension, including newly diagnosed cases, and the levels of awareness, treatment, and control. We also examined predictors of hypertension in this population. To our knowledge, no recent community-based study has comprehensively assessed the full hypertension care cascade including awareness, treatment, and control among adults in Lagos, Nigeria. Our study addresses this gap, providing novel, contemporary insights relevant to both Nigerian public health policy and the wider international community. This study provides up-to-date, community-based data on the hypertension care cascade in Lagos, Nigeria where recent evidence has been scarce. By identifying predictors of hypertension and treatment gaps, it contributes to the understanding of cardiovascular risk patterns in rapidly urbanizing LMIC settings and informs strategies for improved hypertension control.

Methods

Study design and participants

This was a cross-sectional study conducted as part of a community-based blood pressure screening campaign in Lagos, Nigeria. Adults aged 18 years and older were recruited through opportunistic screening at multiple sites across the city. Screening was carried out between June and August 2023. Sociodemographic data and relevant medical history were collected using a standardized study proforma adapted from the WHO STEPS questionnaire as relevant to our study with all information anonymized and de-identified. A total of 1,546 individuals were screened using a non-probability sampling method.

Data collection and instrument

Socio-demographic, lifestyle, and medical history data were obtained using a structured questionnaire developed specifically for this study (Supplementary File 1). The instrument was designed to capture demographic details, history of hypertension and diabetes, blood pressure measurement records, medication use, treatment adherence, and health-care access variables. The tool was developed by the research team based on standard hypertension screening domains and reviewed for face validity before use.

Blood pressure measurement

The blood pressure (BP) of the participants was measured by the trained volunteers using an OMRON M7 Intelli IT device (Stride BP, July 2022) after a 5 min rest. The participants were made to sit upright and comfortably, feet on the floor, and the arm at the level of the heart and free from any constricting clothing. Three BP readings were taken at two-to-three minute intervals and the average was used for classification.

Definition of variables

1. Hypertension: Defined according to the 2018 European Society of Hypertension guidelines (adopted by the Nigerian Hypertension Society) as systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg, or self-reported hypertension/use of antihypertensive medication.

2. Hypertension awareness: Defined as a previous diagnosis of hypertension by a healthcare worker.

3. Hypertension unawareness: Defined as absence of a previous diagnosis of hypertension.

4. High Normal: Defined as previously undiagnosed hypertension with systolic BP 130–139 mmHg and/or diastolic BP 80–89 mmHg according to the European Society of Hypertension (ESH) guidelines of 2023, which recognizes this blood pressure category for cardiovascular risk stratification in adults without established hypertension [22].

5. Isolated systolic hypertension (ISH): Systolic BP ≥140 mmHg with diastolic BP <90 mmHg.

6. Isolated diastolic hypertension: (IDH): Diastolic BP ≥90 mmHg with systolic BP <140 mmHg.

7. Treatment of hypertension: Defined as self-reported use of prescribed antihypertensive medication.

8. Control of hypertension: Defined as systolic BP <140 mmHg and diastolic BP <90 mmHg among participants on treatment.

Statistical analysis

Continuous variables were summarized as mean (standard deviation, SD) for normally distributed data and median (interquartile range, IQR) for skewed data. Categorical variables (e.g., age group, sex, education, body mass index [BMI], tobacco use, alcohol intake, history of diabetes, and physical activity were summarized as frequencies and percentages. Associations between categorical variables and blood pressure category were assessed using the chi-square test of independence, with statistical significance set at p<0.05. Logistic regression analyses were conducted to identify independent predictors of hypertension. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) and p-values were reported. Data analyses were performed using IBM SPSS Statistics version 25 (August 2017). Analyses were conducted using a complete-case approach. Denominators therefore vary across analyses due to item-level non-response. The number of participants included in each analysis is explicitly reported in the text and tables.

Results

General and clinical characteristics of the study population

A total of 1,547 adults participated in the screening, with variable completeness across individual characteristics. Participants were predominantly middle-aged, with a median age of 47 years (IQR 38–57), and there was a slight female predominance (51.2%). Most screenings occurred in hospitals, clinics, or pharmacies (58.3%), followed by public outdoor locations (26.2%). Nearly three-quarters of participants (72.3%) had checked their blood pressure within the preceding 12 months. Overweight and obesity were common, affecting 35.0% and 28.7% of participants, respectively, while 37.8% reported insufficient physical activity. Additional sociodemographic and clinical characteristics are presented in Table 1.

Table 1.

Sociodemographic characteristics of study participants

Variable	Frequency (n = 1547)	Percentage (%)
Screening site location	(n = 1358)
Home	1	0.1
Hospital/Clinic/Pharmacy	791	58.3
Public area (indoors)	10	0.7
Public area (outdoors)	356	26.2
Workplace	200	14.7
Age group (years)	(n = 1484)
18–39 years	401	27.0
40–54 years	625	42.1
55–64 years	281	18.9
65–74 years	133	9.0
≥ 75 years	44	3.0
Median age (IQR)	47.0 (38.0–57.0)
Gender	(n = 1508)
Female	773	51.2
Male	734	48.7
Other	1	0.1
Time since last blood pressure measurement	(n = 1485)
Never	106	7.1
Within the last 12 months	1073	72.3
Over 12 months ago	306	20.6
Current tobacco use (smoking or chewing)	(n = 1482)
Never	889	60.0
No, but I did in the past	531	35.8
Yes	62	4.2
Currently consumes alcohol	(n = 1458)
Never/rarely	1152	79.0
Daily	29	2.0
1–6 times per week	102	7.0
1–3 times per month	175	12.0
History of Diabetes	(n = 1508)
No	1413	93.7
Yes	95	6.3
Performs exercise (≥ 150 min moderate or ≥ 75 min vigorous exercise per week)	(n = 1488)
No	562	37.8
Yes	926	62.2
Number of years of formal education	(n = 1393)
0 years	25	1.8
1–6 years	146	10.5
7–12 years	333	23.9
> 12 years	889	63.8
Body Mass Index (kg/m2)	(n = 1442)
Underweight (< 18.5)	20	1.4
Normal weight (18.5–24.9)	503	34.9
Overweight (25.0–29.9)	505	35.0
Obese (30.0–34.9)	292	20.2
Morbid obesity (≥ 35.0)	122	8.5
Median BMI (IQR)	26.7 (23.6–30.8)

Hypertension prevalence and awareness

Overall hypertension prevalence was 52.5% among screened participants, comprising 34.7% previously diagnosed cases and 17.8% newly detected cases. Among participants without a prior diagnosis of hypertension, 17.8% met diagnostic criteria for hypertension and an additional 25.4% had ‘’high-normal’’ BP pattern. Hypertension prevalence increased progressively with age and was higher among men than women (28.5% vs 23.0%, p=0.015). Isolated systolic and isolated diastolic hypertension were observed in 6.9% and 6.1% of participants, respectively (Table 2).

Table 2.

Prevalence of hypertension among the study participants

Variable	Frequency	Percentage (%)
History of previously diagnosed hypertension (self-reported)	(n = 1492)
No (newly diagnosed)	975	65.3
Yes (previously diagnosed)	517	34.7
Overall blood pressure classification (mmHg)	(n = 1547)
Normal (SBP < 130 and DBP < 80)	748	48.3
High Normal (SBP 130–139 or DBP 80–89)	405	26.2
Hypertension (SBP ≥ 140 or DBP ≥ 90)	394	25.5
Newly diagnosed hypertension (BP ≥ 140/90) in those with no previous diagnosis	(n = 975)
No	801	82.2
Yes	174	17.8
High Normal (SBP 130–139 or DBP 80–89) in those with no previous diagnosis	(n = 975)
No	727	74.6
Yes	248	25.4
Isolated systolic hypertension (SBP ≥ 140 and DBP < 90)	(n = 1547)
No	1441	93.1
Yes	106	6.9
Isolated diastolic hypertension (SBP < 140 and DBP ≥ 90)	(n = 1547)
No	1452	93.9
Yes	95	6.1
Uncontrolled hypertension (BP ≥ 140/90) in those with a previous diagnosis	(n = 517)
No	311	60.2
Yes	206	39.8
Controlled hypertension (BP < 140/90) in those with a previous diagnosis	(n = 517)
No	206	39.8
Yes	311	60.2

Medication use (Treatment and Control)

Table 3 shows the treatment and control profile of the participants. Among participants with a prior diagnosis of hypertension, 39.9% reported current treatment, and 51.9% of these were prescribed two or three antihypertensive medications. The prevalence of controlled hypertension among those on treatment was 60.2%. Payment for care varied: 44.4% reported free consultations, while 57.3% paid out-of-pocket for medications. Most participants (64.6%) described themselves as adherent to treatment, while 36.4% reported non-adherence, citing various reasons.

Table 3.

Hypertension history and practices of study participants

Variable	Frequency (n = 1547)	Percentage (%)
Ever diagnosed with high blood pressure by a health professional (excluding pregnancy-related cases)	(n = 1492)
No	975	65.3
Yes	517	34.7
Age at hypertension diagnosis (years)	(n = 496)
18–39 years	137	27.6
40–54 years	251	50.6
55–64 years	80	16.1
65–74 years	24	4.9
≥ 75 years	4	0.8
Median age at hypertension diagnosis (IQR)	45.0 (38.0–52.8)
Currently taking antihypertensive medication	(n = 1335)
No	802	60.1
Yes	533	39.9
Number of different blood pressure medications being taken	(n = 502)
1	220	43.4
2	184	36.3
3	79	15.6
4	22	4.3
5	2	0.4
Median number of medications taken (IQR)	2.0 (1.0–2.0)
Pays for blood pressure-related consultations	(n = 658)
Not sure if part or fully paid	29	4.4
Pay fully	292	44.4
Pay nothing	265	40.3
Pay part	72	10.9
Pays for blood pressure medication	(n = 620)
Not sure if part or fully paid	39	6.3
Pay fully	355	57.3
Pay nothing	131	21.1
Pay part	95	15.3
Takes blood pressure medication regularly	(n = 523)
I do	338	64.6
I forget	10	1.9
Not easily available	18	3.4
Only take them when I need them	117	22.4
Prefer alternative medicine	10	1.9
Side effects	13	2.5
Too expensive	17	3.3

IQR Interquartile range

Hypertension care cascade

Among participants with hypertension (n=811), only 34.7% were aware of their diagnosis. Treatment uptake was low, with 13.8% of all hypertensive individuals reporting current use of antihypertensive medication. Among those receiving treatment, 60.2% achieved blood pressure control, corresponding to 8.3% of the total hypertensive population. Figure 1 illustrates the marked attrition across the hypertension care cascade, with the largest gaps occurring at the stages of diagnosis and treatment initiation.

Fig. 1.

Hypertension Cascade: Lagos, Nigeria,

Association between the general and clinical characteristics of the study population and their blood pressure patterns

Table 4 presents associations between demographic/clinical factors and blood pressure categories. An age-related gradient was observed, with prevalence increasing significantly with advancing age (p<0.001). Hypertension was more common among men (28.5%) than women (23.0%) (p=0.015). Dietary patterns, educational attainment, medication use (antihypertensives), BMI, and prior history of hypertension, diabetes, heart attack, and heart failure were significantly associated with BP status.

Table 4.

Association between sociodemographic characteristics and blood pressure category

Variable	Blood Pressure category			Test Statistic (χ2)	P-value
	Normal (n = 748) Freq (%)	High Normal (n = 405) Freq (%)	Hypertension (n = 394) Freq (%)
Screening site location	(n = 651)	(n = 354)	(n = 353)
Home	1 (100.0)	0 (0.0)	0 (0.0)	15.096	0.057
Hospital/Clinic/Pharmacy	384 (48.5)	223 (28.2)	184 (23.3)
Public area (indoors)	6 (60.0)	2 (20.0)	2 (20.0)
Public area (outdoors)	158 (44.4)	81 (22.7)	117 (32.9)
Workplace	102 (51.0)	48 (24.0)	50 (25.0)
Age group (years)	(n = 712)	(n = 387)	(n = 385)
18–39 years	277 (69.1)	75 (18.7)	49 (12.2)	109.166	< 0.001
40–54 years	263 (42.1)	183 (29.3)	179 (28.6)
55–64 years	104 (37.0)	82 (29.2)	95 (33.8)
65–74 years	55 (41.3)	34 (25.6)	44 (33.1)
≥ 75 years	13 (29.5)	13 (29.5)	18 (41.0)
Median age (IQR)	43.0 (33.0–54.0)	48.0 (40.0–57.0)	50.0 (45.0–60.0)	204.501	< 0.001 #
Gender	(n = 724)	(n = 397)	(n = 387)
Female	402 (52.0)	193 (25.0)	178 (23.0)	12.343	0.015
Male	321 (43.7)	204 (27.8)	209 (28.5)
Other	1 (100.0)	0 (0.0)	0 (0.0)
Time since last blood pressure measurement	(n = 712)	(n = 394)	(n = 379)
Never	69 (65.1)	23 (21.7)	14 (13.2)	16.384	0.003
Within the last 12 months	510 (47.5)	283 (26.4)	280 (26.1)
Over 12 months ago	133 (43.5)	88 (28.7)	85 (27.8)
Ever diagnosed with high blood pressure by a health professional	(n = 719)	(n = 393)	(n = 380)
No	553 (56.7)	248 (25.4)	174 (17.9)	107.532	< 0.001
Yes	166 (32.1)	145 (28.1)	206 (39.8)
Currently taking antihypertensive medication	(n = 649)	(n = 335)	(n = 351)
No	459 (57.2)	195 (24.3)	148 (18.5)	78.113	< 0.001
Yes	190 (35.6)	140 (26.3)	203 (38.1)
Current tobacco use (smoking or chewing)	(n = 717)	(n = 384)	(n = 381)
Never	453 (51.0)	224 (25.2)	212 (23.8)	6.653	0.155
No, but I did in the past	237 (44.6)	144 (27.1)	150 (28.3)
Yes	27 (43.6)	16 (25.8)	19 (30.6)
Currently consumes alcohol	(n = 706)	(n = 379)	(n = 373)
Never/rarely	561 (48.7)	308 (26.7)	283 (24.6)	11.055	0.087
Daily	11 (37.9)	11 (37.9)	7 (24.2)
1–6 times per week	46 (45.1)	29 (28.4)	27 (26.5)
1–3 times per month	88 (50.3)	31 (17.7)	56 (32.0)
History of diabetes	(n = 720)	(n = 401)	(n = 387)
No	682 (48.3)	379 (26.8)	352 (24.9)	6.661	0.036
Yes	38 (40.0)	22 (23.2)	35 (36.8)
Performs exercise (≥ 150 min moderate or ≥ 75 min vigorous exercise per week)	(n = 715)	(n = 389)	(n = 384)
No	259 (46.1)	156 (27.8)	147 (26.1)	1.671	0.434
Yes	456 (49.2)	233 (25.2)	237 (25.6)
Number of years of formal education	(n = 686)	(n = 357)	(n = 350)
0 years	4 (16.0)	12 (48.0)	9 (36.0)	13.477	0.036
1–6 years	67 (45.9)	40 (27.4)	39 (26.7)
7–12 years	163 (49.0)	88 (26.4)	82 (24.6)
> 12 years	452 (50.8)	217 (24.4)	220 (24.8)
Body Mass Index (kg/m2)	(n = 703)	(n = 374)	(n = 365)
Underweight (< 18.5)	17 (85.0)	1 (5.0)	2 (10.0)	40.360	< 0.001
Normal weight (18.5–24.9)	282 (56.1)	127 (25.2)	94 (18.7)
Overweight (25.0–29.9)	233 (46.1)	138 (27.3)	134 (26.6)
Obese (30.0–34.9)	117 (40.1)	78 (26.7)	97 (33.2)
Morbid obesity (≥ 35.0)	54 (44.3)	30 (24.6)	38 (31.1)
Median BMI (IQR)	25.7 (22.5–29.8)	27.2 (23.9–30.9)	28.2 (24.9–31.6)	89.499	< 0.001 #

χ2 = Chi-square Test; ^# = Kruskal-Wallis H Test; IQR Interquartile range

Bold p-values indicate statistical significance at p < 0.05

Ordinal logistic regression of predictors of blood pressure category

Table 5 shows the results from the ordinal logistic regression model, providing insight into factors associated with increasing levels of BP. Younger age (18–39 years) and female gender were significantly associated lower odds of having higher blood pressure category: (AOR = 0.38; 95% CI 0.17–0.85; p = 0.019), (AOR = 0.73; 95% CI 0.55–0.98; p =0.035) respectively. Having checked blood pressure within the last 12 months and no prior diagnosis of hypertension were significantly associated with lower odds of having a higher blood pressure category (AOR = 0.59; 95% CI 0.41–0.85; p = 0.005) and (AOR = 0.41; 95% CI 0.27–0.62; p < 0.001) respectively. On the contrary prior diagnosis of hypertension and lack of formal education were significantly associated with higher odds of higher blood pressure category. Non-obese BMI ranges were significantly associated with lower odds of higher blood pressure category.

Table 5.

Ordinal logistic regression of predictors of Raised blood pressure

Variable	Adjusted Odds Ratio	95% Confidence Interval	P-value
Age group (years)
18–39 years	0.38	0.17–0.85	0.019
40–54 years	0.95	0.44–2.05	0.890
55–64 years	0.84	0.38–2.04	0.660
65–74 years	0.51	0.22–1.21	0.126
≥ 75 years	Reference (1.00)	-	-
Gender
Female	0.73	0.55–0.98	0.035
Male	Reference (1.00)	-	-
Time since last blood pressure measurement
Never	0.79	0.43–1.45	0.441
Within the last 12 months	0.59	0.41–0.85	0.005
Over 12 months ago	Reference (1.00)	-	-
Ever diagnosed with high blood pressure by a health professional
No	0.41	0.27–0.62	< 0.001
Yes	Reference (1.00)	-	-
Currently taking antihypertensive medication
No	1.03	0.68–1.56	0.899
Yes	Reference (1.00)	-	-
History of diabetes
No	1.36	0.78–2.36	0.276
Yes	Reference (1.00)	-	-
Number of years of formal education
0 years	2.57	1.09–6.09	0.032
1–6 years	1.24	0.73–2.13	0.431
7–12 years	1.02	0.71–1.45	0.915
> 12 years	Reference (1.00)	-	-
Body Mass Index (kg/m2)
Underweight (< 18.5)	0.12	0.02–0.91	0.040
Normal weight (18.5–24.9)	0.44	0.26–0.75	0.003
Overweight (25.0–29.9)	0.59	0.36–0.97	0.039
Obese (30.0–34.9)	0.63	0.37–1.07	0.084
Morbid obesity (≥ 35.0)	Reference (1.00)	-	-

Bold p-values indicate statistical significance at p < 0.05

Discussion

Our survey contributes to the growing body of knowledge on hypertension prevalence, awareness, and control in Nigeria. We found a prevalence of 52.5% (34.7% previously diagnosed and 17.8% newly diagnosed), which is considerably higher than the nationwide prevalence of 38.1% reported in 2017 [4]. Published studies place the prevalence in Lagos, Nigeria between 27.5% and 55%, depending on the study population and diagnostic criteria [19, 23–26]. This ranks Lagos among the Nigerian cities with the highest prevalence, comparable to Port Harcourt (40.8%), Kano (37.1%), and Abuja (38.3%) [27–29]. Within sub-Saharan Africa (SSA), prevalence is reported as 30.3% in Accra, 38.9% in Cape Town, and 25.6% in Nairobi [30–32]. Globally, comparable cities report lower levels: New York City (25.6%), London (32%), Mumbai (30%), and Beijing (35.5%) [33–36]. The high burden observed in Lagos, Nigeria may reflect rapid urbanization, population expansion, lifestyle transitions, rising obesity, and socioeconomic stressors [23, 24, 37, 38]. This finding is concerning in the context of a health system already challenged by the double burden of communicable and non-communicable diseases [39]. The problem is worsened by shortages of healthcare workers due to migration to high-income countries (HICs). Primary prevention remains the first line of response, emphasizing physical activity, maintenance of healthy weight, moderation of alcohol use, smoking cessation, and adoption of the DASH diet [40]. These non-pharmacological measures must be complemented by affordable, high-quality generic antihypertensive medications, as promoted in the WHO HEARTS package, to reduce cardiovascular morbidity and mortality [41]. In addition, universal health insurance or other financing mechanisms are essential to minimize out-of-pocket spending and improve treatment adherence.

Our findings also confirm the alarmingly low awareness of hypertension in Lagos, Nigeria. Prior studies reported awareness rates of 60.3–81.8%, underscoring gaps in the care cascade [23, 24, 42]. We found 65.3% of hypertensive participants were unaware of their condition, compared with 40–71% in national data [6, 7]. Globally, the prevalence of unawareness is about 46%, with wide disparities [1]. Rates are consistently lower in HICs than in LMICs [1, 9, 43, 44]. In SSA, unawareness can be as high as 92% depending on the population [9, 44, 45]. By contrast, New York City and London report much lower rates of 20% and 35%, respectively [46, 47]. In Nigeria, studies report unawareness between 35% and 71%, highlighting persistent gaps in detection [7, 8, 23, 24, 42]. Unawareness is dangerous because it increases the risk of hypertension-mediated organ damage, including stroke, heart failure, chronic kidney disease, premature death, and substantial healthcare costs. The high level of unawareness in Lagos, Nigeria may be associated with high rates of cardiovascular admissions and deaths observed in the city [20, 21]. Addressing this requires multi-pronged strategies: large-scale opportunistic screening campaigns, integration of screening into primary care, task-shifting and task-sharing, health system strengthening, community engagement, culturally tailored approaches, and financing/policy interventions [41, 45, 48–51]. Together, these efforts could substantially reduce the hidden pool of undiagnosed hypertension and improve the care cascade.

Treatment and control are critical for preventing complications. In Lagos and other Nigerian cities, both are generally poor, often below 50%, and sometimes as low as 20–30% in community samples, though higher coverage is reported in health facility settings [6, 7, 52]. In our study, treatment uptake was 39.9%, higher than the 24.6% previously reported among traders in Lagos [23]. Nationally, treatment rates range between 12% and 40.9% [6, 7]. In SSA, uptake is between 18% and 26%, while HICs achieve over 50% coverage [1, 9, 44, 45, 50]. Encouragingly, we observed a hypertension control rate of 60.2%, far higher than most national and SSA studies, which often report control rates below 20%. In contrast, HICs report much higher rates, explaining their lower burden of hypertension-related morbidity and mortality [1, 9]. The cascade (Fig. 1) underscores that the major attrition in hypertension care in Lagos occurs at the stages of awareness and treatment initiation, while control among those treated was comparatively high. This pattern indicates that and programmatic interventions should focus primarily on improving detection and access to therapy.

We also found clear age and gender disparities. Prevalence increased with age and was higher in men, consistent with prior studies [1, 7, 8, 45, 48, 53]. Globally, hypertension prevalence rises with age, with lifetime risk reaching 90% among normotensive adults by age 55 [2, 54, 55]. Risk is strongly influenced by life expectancy and exposure to risk factors. Lifetime risk is 85–90% in HICs but 70–85% in LMICs, and is expected to increase as life expectancy improves [1, 2, 55]. With respect to gender, prevalence follows a “cross phenomenon”: men generally have higher rates at younger ages, but after menopause, women’s prevalence equals or exceeds that of men [1, 2, 55, 56]. In SSA, the female advantage is lost at older ages, with women showing similar or higher prevalence [57, 58]. Hormonal, vascular, cultural, and urbanization factors likely explain this transition [53, 56–59]. Addressing these sex- and age-specific risks is crucial for effective prevention and lifelong control.

Our study, with its large sample size, highlights the heavy burden of hypertension in Lagos, Nigeria’s most populous and cosmopolitan city. It also reveals alarmingly low awareness and gaps in treatment and control. Nonetheless, several limitations exist. Opportunistic screening may overestimate hypertension prevalence due to non-probability sampling, stressful screening environments, and the absence of confirmatory blood pressure measurements. In addition, blood pressure was measured during a single visit, which may have resulted in misclassification and inflated prevalence estimates. These factors limit the generalizability of our findings. Self-reported data are also subject to recall and social desirability bias. Additionally, comparative data were drawn from studies with heterogeneous methods, which may account for some observed differences. Despite these limitations, opportunistic screening remains a cost-effective strategy for identifying undiagnosed hypertension and linking individuals to care. The findings from our study, though conducted in Lagos, Nigeria, are likely relevant to other rapidly urbanizing African cities where similar demographic and lifestyle patterns exist. Future studies should assess longitudinal trends and evaluate scalable interventions to enhance awareness and control of hypertension.

Conclusion

Opportunistic community-based screening revealed the substantial contemporary burden of hypertension in Lagos, Nigeria, including high prevalence, significant unawareness, and suboptimal treatment coverage. These findings highlight the need for enhanced population-wide screening, stronger primary care services, and improved access to affordable antihypertensive medications to address care gaps. By addressing these gaps, Lagos, Nigeria can make meaningful progress in reducing cardiovascular morbidity and mortality and serve as a model for other rapidly urbanizing cities in low- and middle-income countries. Importantly, this study provides recent, city-specific data that can inform hypertension control strategies in other rapidly urbanizing regions of sub-Saharan Africa and similar LMIC settings.

Abbreviations

BP

Blood pressure

LMIC

Low- and middle-income countries

WHO

World health organization

ESH

European society of hypertension

NHS

Nigerian hypertension society

BMI

Body mass index

Authors’ contributions

CEA, OKA, ACM and JNA conceptualized the research. CEA, OKA, UCO, MNO and POA acquired the data. UCO, MNO and POA curated the data for analysis. CEA, UCO and MNO drafted the manuscript. ACM, OKA and JNA reviewed the draft of the manuscript. All authors read and approved the final draft of the manuscript for submission for publication.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. The English version of the survey instrument is available as Supplementary File 1.

Declarations

Ethics approval and consent to participate

Ethical approval was obtained from the Health Research Ethics Committee of Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria (Reference: ADM/DSCST/HREC/APP/6494). Written informed consent was obtained from all participants prior to data collection, and all data were de-identified and anonymized in accordance with the Declaration of Helsinki. Participants with severe hypertension were promptly referred to either their primary care physician or to the primary healthcare center closest to them. They were followed up with phone calls by one of the investigators (ACE) to ensure they visited the medical facilities for treatment and follow-up.

Consent for publication

Not applicable. This manuscript does not contain any individual person’s identifiable data.

Competing interests

The authors declare no competing interests.