Lack of relationship between hypertension-associated symptoms and blood pressure in hypertensive ED patients

Symptom experiences in hypertension: a mixed methods systematic review

AIM

Understanding patients' hypertension (HTN) symptoms can assist healthcare professionals' awareness of individual, cultural, and behavioral responses and improve diagnostic accuracy to optimize treatment. The purpose of this review was to evaluate and synthesize current literature exploring HTN symptoms.

METHODS

Databases searched included MEDLINE (PubMed), CINAHL (EBSCO), Scopus, and Web of Science from January 2010 to January 2022. The search followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The McMaster critical review forms were used to determine the quality of both qualitative and quantitative articles. Synthesis of the data was guided by the Joanna Briggs Institute Convergent Integrated Approach to Mixed Study Systematic Reviews.

RESULTS

In total, 41 articles were included, nine qualitative studies and 32 quantitative. The quality of the articles varied. Symptoms included commonly reported symptoms and some less prevalent, including some reporting absence of symptoms. Factors that affected symptoms included culture, beliefs, psychosocial factors, and knowledge. We also found that there may be a bidirectional relationship between symptoms and behaviors that may lead to self-management.

CONCLUSION

HTN is common and symptoms are frequently reported. HTN management is related to multiple factors. Symptoms continue in a number of individuals after initial diagnosis. Evaluating symptoms after initial diagnosis may help to optimally manage and meet blood pressure guidelines.

Relationships among Clinical Factors and Patient-reported Outcome Measures in Adults with Convergence Insufficiency

SIGNIFICANCE

When exploring relationships among clinical measures and patient-reported outcome measures in adults with convergence insufficiency, worse symptoms (Convergence Insufficiency Symptom Survey [CISS] score) seemed to be correlated with worse reading function domain score (Adult Strabismus-20 quality-of-life questionnaire). After treatment, improved symptoms were associated with improved reading function quality of life.

PURPOSE

This study aimed to explore relationships between clinical measures and patient-reported outcome measures in adults undergoing treatment for symptomatic convergence insufficiency.

METHODS

In a prospective multicenter observational study, we evaluated adults with symptomatic convergence insufficiency (i.e., clinical measures of near exodeviation, receded near point of convergence, reduced near positive fusional vergence; CISS score ≥21). Fifty-seven participants treated with vision therapy/exercises (n = 35) or base-in prism (n = 22) were analyzed. Spearman correlation coefficients ( R ) were used to assess associations among the three clinical measures and patient-reported outcome measures (CISS, Diplopia Questionnaire, four Adult Strabismus-20 quality-of-life domains) before treatment (baseline) and after 10 weeks and 1 year. Associations were interpreted to be present when the lower limit of the 95% confidence interval (CI) was moderate to strong ( R ≥ 0.4).

RESULTS

Among multiple exploratory analyses, the only moderate to strong baseline correlation was between worse CISS and worse Adult Strabismus-20 reading function scores ( R = 0.62; 95% CI, 0.43 to 0.76). Regarding change in measures with treatment, the only moderate to strong correlations were between improved CISS and improved Adult Strabismus-20 reading function scores for prism at 10 weeks ( R = 0.78; 95% CI, 0.52 to 0.91) and 1 year ( R = 0.85; 95% CI, 0.65 to 0.94) and for vision therapy/exercises at 1 year ( R = 0.78; 95% CI, 0.57 to 0.89).

CONCLUSIONS

In exploratory analyses, we found positive correlations between CISS symptom scores and reading function quality-of-life scores. The absence of correlations between symptoms and individual clinical measures is consistent with clinical experience that, in convergence insufficiency, symptoms and clinical findings can be discordant.

Just the Facts: Hypertension in the emergency department

A 65-year-old female smoker complains of dizziness and mild headache. While at the local pharmacy buying acetaminophen, she decides to check her blood pressure to see if it could be "causing her symptoms." Her initial measurement is 220/96 mm Hg. In consultation with the on-duty pharmacist she is instructed to immediately attend the emergency department (ED) for management of her hypertension.

National trends in U.S. emergency department visits for chief complaint of hypertension (2006-15)

OBJECTIVES

Hypertension is one of the most common chronic illnesses among adults in the United States. While poor hypertension control is a risk factor for many emergent conditions, asymptomatic hypertension is rarely an emergency. Despite this, patients may present to the emergency department (ED) with a chief complaint of hypertension, and there may be significant variability in the management of these patients. Our objective was to characterize national trends in ED visits for chief complaint of hypertension between 2006 and 2015.

METHODS

We used the National Hospital Ambulatory Medical Care Survey (NHAMCS) from 2006 to 2015 to examine ED visits for chief complaint of hypertension. We examined trends in demographics, diagnostic resource utilization, and clinical management of these patients.

RESULTS

Between 2006 and 2015, visits with hypertension as the primary chief complaint represented 0.6% of all ED visits, or 6,215,787 national-level ED visits. Of these, 63.9% received a primary diagnosis of hypertension. While there was no significant growth in these visits over the study period, 79.3% of visits received any form of diagnostic testing, with 35.5% of patients receiving an antihypertensive medication. Increasing blood pressure and non-white race were associated with increased odds of receiving antihypertensive medications.

CONCLUSIONS

Despite clinical policies and guidelines recommending against routine diagnostic testing for asymptomatic hypertension, roughly 4 out of 5 ED visits received diagnostic testing, and more than 1 out of 3 received medications. These visits may represent an opportunity for improvement to reduce overutilization, as well as for innovative approaches as EDs expand their role in care coordination across settings.

Is epistaxis associated with high blood pressure and hypertension? Propensity score matching study

OBJECTIVE

We aimed to investigate whether high blood pressure and hypertension are associated with epistaxis.

METHODS

A retrospective study with a propensity score matching analysis was performed at the emergency departments (EDs) of a tertiary university hospital. The mean blood pressure (BP, systolic and diastolic) and proportion of subjects with elevated BP (systolic >120 and/or diastolic >80 mmHg) at presentation were compared between the epistaxis group and matched control group. The proportion of patients with newly diagnosed hypertension within six months between the two groups was also compared.

RESULTS

A total of 1353 patients with epistaxis and the same number of those with simple lacerations were matched. The mean systolic and diastolic BPs of the epistaxis group were significantly higher than those of the matched control group (157.1 ± 26.4 and 91.4 ± 17.0 mmHg versus 144.9 ± 32.4 and 84.2 ± 13.5 mmHg) (P < 0.001). The proportion of patients with elevated BP at presentation was also significantly higher in the epistaxis group (91.4%) than in the matched control group (86.2%) (P < 0.001). Of the 724 (53.5%) patients without pre-existing hypertension in the epistaxis group, 660 patients were followed, of whom 107 (16.2%) were newly diagnosed with hypertension within 6 months, which was a significantly higher percentage than among the matched controls (4.9%, P < 0.001) CONCLUSION: The patients with epistaxis had elevated BP at presentation and a higher proportion of newly diagnosed hypertension within six months compared to the matched controls.

[Severe high blood pressure recently diagnosed in an urban milieu from Subsahelian Africa: Epidemiologic, clinical, therapeutic and evolutionary aspects]

OBJECTIVES

High Blood Pressure (HBP) is a worldwide public health problem. It can be particularly severe in the Black race. Recent studies in Cameroon, showed an alarming prevalence, leading us to want to study the epidemiological, clinical, therapeutic and evaluative aspects of severe, (BP op to 180/110mmHg), recently diagnosed HBP in Yaounde. Our objective was to determine its clinical presentation and evolution.

METHODS

We conducted nine months prospective cohort study, from January to September 2016. We recruited from the active population participants who voluntarily accepted blood pressure screening offered in various localities in Yaounde, and were aged from 18 years and above.

RESULTS

Of a total of 6519 people who participated in the screening, 1875 (28.8%.), presented a HBP and 363 (5.6%) had severe HBP. Our cohort comprised 153 (42.1%) of these individuals with sustained severe hypertension, not on medication, who accepted the invitation to participate in the study. The range of 45-54 years and 55-64 years were the most represented; the sex ratio was 0.9. The cardiovascular risk factors number range from 5 to 8 with a median of 6. Systolic BP ranged from 184 to 225mmHg with a median of 200mmHg; while the diastolic BP ranged between 111-132.5mmHg with a median of 119mmHg. Kidney injury (77.8%) was the main complications. We identified 3 clinical forms: hypertensive emergencies 121 (79.1%) cases and hypertensive crises 32 (20.9%) cases. In these two groups, 33 (21.6%) patients presented with "super HBP" (a blood pressure>250/150mmHg). The average rate of BP control over 6 month was 39%. The main cause of poor BP control was lack of therapeutic compliance. We registered one death at the 3rd month of follow up due to acute kidney injury.

CONCLUSION

Severe HBP prevalence in Yaounde is high in the active fraction of the population insidiously affected. Particularly, unsuspected renal impairment appears to be the major complication. The bad blood pressure control is linked to poor therapeutic observance and persistence.

The significance of atherosclerosis in hypertensive patients with epistaxis

BACKGROUND

The relationship between hypertension and epistaxis is controversial and poorly understood. The present research investigated atherosclerosis as a potential risk factor in hypertensive patients with epistaxis.

METHODS

A prospective study of 141 hypertensive patients with epistaxis was conducted. The laboratory tests included full blood count, lipid profile and coagulation profile. All patients underwent funduscopic examination of the eye and were classified in terms of four retinopathy grades.

RESULTS

There were strong positive correlations between the number of nosebleeds and retinopathy grade and low-density lipoprotein cholesterol level. There were weak correlations between the number of nosebleeds and blood pressure readings and triglycerides levels. Patients with grade III retinopathy, suggesting atherosclerosis, suffered from more frequent nosebleeds than other patients.

CONCLUSION

Atherosclerosis is one of the potential risk factors in hypertensive patients with epistaxis. This may have an impact on treatment choices.

Association between Hypertension and Epistaxis: Systematic Review and Meta-analysis

Objective Whether there is an association or a cause-and-effect relationship between epistaxis and hypertension is a subject of longstanding controversy. The objective of this systematic review and meta-analysis was to determine the association between epistaxis and hypertension and to verify whether hypertension is an independent risk factor of epistaxis. Data Sources A comprehensive search was performed using the MEDLINE, EMBASE, and Cochrane Library databases. Review Methods The review was performed according to the Meta-analysis of Observational Studies in Epidemiology guidelines and reported using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Results We screened 2768 unique studies and selected 10 for this meta-analysis. Overall, the risk of epistaxis was significantly increased for patients with hypertension (odds ratio, 1.532 [95% confidence interval (CI), 1.181-1.986]; number needed to treat, 14.9 [95% CI, 12.3-19.0]). Results of the Q test and I² statistics suggested considerable heterogeneity ([Formula: see text] = 0.038, I² = 49.3%). The sensitivity analysis was performed by excluding 1 study at a time, and it revealed no change in statistical significance. Conclusion Although this meta-analysis had some limitations, our study demonstrated that hypertension was significantly associated with the risk of epistaxis. However, since this association does not support a causal relationship between hypertension and epistaxis, further clinical trials with large patient populations will be required to determine the impact of hypertension on epistaxis.

Characterization and history of arterial hypertension leading to inpatient treatment

Background and aims

Methods

Results

Conclusion

Hypertension in the Emergency Department

Hypertension is the leading risk factor for the global burden of disease, yet more than 20% of adults with hypertension are unaware of their condition. Underlying hypertension affects over 25% emergency department attendees, and the condition is more commonly encountered in emergency departments than in primary care settings. Emergency departments are strategically well placed to fulfill the important public health goal of screening for hypertension, yet less than 30% of patients with mild to severe hypertension are referred for follow up. In predominantly African American populations, subclinical hypertensive disease is highly prevalent in ED attendees with asymptomatic elevated blood pressure. Although medical intervention is not usually required, in select patient populations, it may be beneficial for antihypertensive medications to be started or adjusted in the emergency department, aiming for optimizing blood pressure control earlier while waiting for continuing care.

Relationship between epistaxis and hypertension: A cause and effect or coincidence?

Introduction

Epistaxis is the most common otorhinolaryngological emergency. Whether there is an association or cause and effect relationship between epistaxis and hypertension is a subject of longstanding controversy.

Objective

The aim of our study is to evaluate the relationship between epistaxis and hypertension.

Materials and methods

This study was conducted at Olaya Medical Center (Riyadh) during the period between May 2013 and June 2014. A total of 80 patients were divided into two groups: Group A consisted of 40 patients who presented with epistaxis, and Group B consisted of 40 patients who served as a control group. Twenty-four-hour ambulatory blood pressure monitoring (ABPM) was performed for all patients. Patients were followed up for a period of three months.

Results

Readings of blood pressure (BP) were similar between the two groups regarding BP at presentation, ABPM, and BP at three months. There was a higher number of attacks in patients with history of hypertension. There was highly significant positive correlation between number of attacks of epistaxis and BP readings. Systolic BP at presentation was higher in patients who needed more complex interventions such as pack, balloon or cautery than those managed by first aid.

Conclusion

We found no definite association between epistaxis and hypertension. Epistaxis was not initiated by high BP but was more difficult to control in hypertensive patients.

Differences and similarities in explanatory models of hypertension in the United States of america, Tanzania and Jamaica

BACKGROUND

Misperceptions detract from effective disease management in a number of conditions but the nature of underlying illness beliefs and their relative consistency in patients with chronic hypertension (cHTN) who present to the Emergency Department (ED) with poor blood pressure control is not known.

OBJECTIVES

1) To explore disease knowledge in ED patients with cHTN using explanatory modelling; and 2) to compare gaps in cHTN knowledge across racially similar but geographically divergent ED patients.

METHODS

Emergency department patients of African origin with cHTN were recruited from three sites: Detroit Receiving Hospital (DRH - Detroit, MI), the Tanzanian Training Center for International Health (TTCIH - Ifakara, TZ) and the University Hospital of the West Indies (UHWI - Kingston, JA). Demographic and baseline data were collected along with open-ended responses to a series of questions related to cHTN. Qualitative responses were coded into predefined, disease-relevant quantitative domains by two separate, blinded reviewers and multilevel comparisons were performed using Kruskal-Wallis or analysis of variance (ANOVA) tests, where appropriate.

RESULTS

One hundred and ninety-seven patients were enrolled; mean age (50.5 years vs 51.6 years vs 50.8 years; p = 0.86) and gender distribution (% male: 49.5 vs 44 vs 40; p = 0.53) were similar across sites but patients at DRH (vs TTCIH vs UHWI) were more hypertensive at presentation (mean systolic BP in mmHg: 166.8 vs 153 vs 152.7; p = 0.003), had a longer mean duration of cHTN (12.1 years vs 4.6 years vs 9.1; p < 0.0001), and were less likely to be on antihypertensive therapy (84.5% vs 92% vs 100%, p = 0.001). Explanatory models revealed limited recognition of cHTN as a "disease" (19.6% vs 28% vs 16%; p = 0.31) and consistency in the belief that cHTN was curable (44.3% vs 36% vs 42%; p = 0.62). Stress (48.4% vs 60% vs 50%; p = 0.31) and, especially at DRH, diet (62.2% vs 22% vs 36%; p < 0.0001) were identified most frequently as causes of cHTN and an association with symptoms was common (83.5% vs 98% vs 78%; p = 0.15). Clear differences existed for perceived benefits of treatment and consequences of poor control by site, but in general, both were under-appreciated.

CONCLUSIONS

Misperceptions related to cHTN are common in ED patients. While specific areas of disconnect exist by geographic region, failure to recognize cHTN as a dire and fixed disease state is consistent, suggesting that a uniform educational intervention may be of benefit in this setting.

High-Risk Patients with Hypertension: Clinical Management Options

Hypertension, one of the most common human diseases worldwide, affects nearly 1 billion individuals. Complaints related to hypertension are commonly evaluated and treated in the acute care settings such as emergency departments and acute care medical clinics. The evaluation, treatment, and disposition of these patients require thorough knowledge of potential complications and treatment options. This manuscript details a structured approach to evaluating high-risk patients with acute hypertension-related complaints and provides recommendations for treatment and disposition.

Initial approach to hypertension in the hemodynamics unit: review article

Correct identification and early management of hypertensive disorders should be a part of the therapeutic repertoire of every professional working in hemodynamics units. Based on recent publications, this study aims to propose a practical approach to the identification and early management of these disorders in this type of service.

Intravenous nicardipine and labetalol use in hypertensive patients with signs or symptoms suggestive of end-organ damage in the emergency department: a subgroup analysis of the CLUE trial

OBJECTIVE

To compare the efficacy of Food and Drug Administration recommended dosing of nicardipine versus labetalol for the management of hypertensive patients with signs and/or symptoms (S/S) suggestive of end-organ damage (EOD).

DESIGN

Secondary analysis of the multicentre prospective, randomised CLUE trial.

SETTING

13 academic emergency departments in the USA.

PARTICIPANTS

Eligible patients had two systolic blood pressure (SBP) measures ≥180 mm Hg at least 10 min apart, no contraindications to nicardipine or labetalol and predefined S/S suggestive of EOD on arrival.

INTERVENTIONS

Medications were administered by continuous infusion (nicardipine) or repeat intravenous bolus (labetalol) for a study period of 30 min or until a specified target SBP ±20 mm Hg was achieved.

PRIMARY OUTCOME MEASURE

Percentage of participants achieving a predefined target SBP range (TR) defined as an SBP within ±20 mm Hg as established by the treating physician.

RESULTS

Of the 141 eligible patients, 49.6% received nicardipine, 51.7% were women and 81.6% were black. Mean age was 52.2±13.9 years. Median initial SBP did not differ in the nicardipine (210.5 (IQR 197-226) mm Hg) and labetalol (210 (200-226) mm Hg) groups (p=0.862). Nicardipine patients were more likely to have a history of diabetes (41.4% vs 25.7%, p=0.05) but there were no other historical, demographic or laboratory differences between groups. Within 30 min, nicardipine patients more often reached the target SBP range than those receiving labetalol (91.4% vs 76.1%, difference=15.3% (95% CI 3.5% to 27.3%); p=0.01). On multivariable modelling with adjustment for gender and clinical site, nicardipine patients were more likely to be in TR by 30 min than patients receiving labetalol (OR 3.65, 95% CI 1.31 to 10.18, C statistic=0.72).

CONCLUSIONS

In the setting of hypertension with suspected EOD, patients treated with nicardipine are more likely to reach prespecified SBP targets within 30 min than patients receiving labetalol.

CLINICAL TRIAL REGISTRATION

NCT00765648, clinicaltrials.gov.

[High blood pressure in the emergency department: epidemiology and evaluation of a dedicated consultation]

OBJECTIVES

The Arterial High blood pressure represents a consultation on 5 in general medicine. The main objective of our study was to estimate patients' proportion appearing at emergency department (ED) with a high Blood pressure and to demonstrate that it is possible to detect the patients at risk of essential and secondary hypertension as well as their cardiovascular risk there.

METHODS

Non-interventional forward-looking Study led over 6 weeks. After measure of the vital parameters in the reception of ED, the patients were included if the Systolic Blood Pressure (SBP) was ≥ 140 mmHg and\or Diastolic Blood Pressure (DBP) ≥ 90 mmHg. A control of Blood Pressure (BP) was made at least 40 minutes after the inclusion. If the Arterial High blood pressure persisted (BP ≥ 140/90 mmHg and age < 30 years or BP ≥ 180/110 mmHg after 30 years), the patients had to see again a cardiologist of the hospital in 7 days because they were considered as at high cardiovascular risk.

RESULTS

A high initial BP was discovered to 582 (8,7 %) 6685 patients having consulted in ED during the period of the study. 64 % of them (n = 372) had a persistent Arterial High Blood pressure after 40 minutes. 27 patients, defined at high cardiovascular risk had a proposition of consultation of cardiology, appeared 11 to it. 4 secondary hypertension was discovered.

CONCLUSION

During the period of study, 582 patients presented a High BP. To 64 % of those who had a control of BP this imbalance was confirmed. The patients (n=27) presenting a high cardiovascular risk had a proposition of fast consultation. This one allowed discovering 4 secondary hypertension. There is thus a utility to estimate the BP in a systematic way at Emergency Department.

Pitfalls in the management of headache in the emergency department

Headache is the fifth most common primary complaint of patients presenting to an emergency department (ED) in the United States. The emergency physician (EP) plays a unique role in the management of these patients, one that differs from that of the primary care physician, the neurologist, and other specialists. Diagnostic nomenclature used in the ED is necessarily less specific, as care is more appropriately focused on the relief of symptoms and the identification of life-threatening causes. By seeking a limited number of specific critical features on history and physical examination, the EP can minimize the risk of overlooking one of these dangerous causes of headache. When certain features are present, empirical therapies and diagnostic testing should be initiated in the ED. The most frequently encountered pitfalls in the management of patients with headache in emergency medicine practice, and those with the greatest likelihood to adversely affect patient outcomes, are discussed.

Intravenous clevidipine for management of hypertension

Hypertension remains one of the most prevalent diseases affecting our society, and its complications lead the list of causes of mortality all over the world. Most efforts to control the disease are unsuccessful, failing in at least two-thirds of affected patients, despite the availability of multiple drugs for its treatment. The limited number of medications available for aggressive management of hypertensive crises has intensified the search for novel drugs that can achieve a rapid decrease in blood pressure without increasing the possible complications. Clevidipine is a novel, vasculoselective, dihydropyridine calcium channel blocker characterized by a very fast onset and offset of action. Metabolism of clevidipine does not occur in the liver or kidneys, and thus there are no restrictions to using clevidipine in patients with hepatic or renal dysfunction. This agent has been widely used to reduce blood pressure when oral therapy is not appropriate, and its use in the perioperative setting has been shown to be beneficial. This manuscript reviews the key characteristics of clevidipine and its role in the management of acute hypertension.

Asymptomatic hypertension in the emergency department: a matter of critical public health importance

Asymptomatic hypertension (HTN) is commonly encountered in the emergency department (ED), but in most circumstances little is done about it. While many factors may contribute to this, the failure to recognize asymptomatic HTN as a public health problem is particularly important. Given the established long-term consequences of elevated blood pressure (BP), a reconsideration of methods that could enhance surveillance and intervention in the ED is needed. In this article, we discuss the relevant epidemiology of asymptomatic HTN and present a novel approach using a modified version of the Haddon's matrix to systematically address the challenges that contribute to ineffective screening and suboptimal outcomes.

Association between epistaxis and hypertension: a one year follow-up after an index episode of nose bleeding in hypertensive patients

Association between epistaxis and hypertension is controversial. In this study, we evaluated in hypertensive patients the incidence of epistaxis according to stages of hypertension and compared blood pressure (BP) readings in these episodes to routine readings. Thirty-six patients admitted to the Emergency Department (ED) with epistaxis were enrolled and divided into 3 groups according to hypertension severity (JNC-VI criteria). BP readings were obtained weekly (routine BP) and in the setting of a new episode of epistaxis (epistaxis BP). No difference in the incidence of epistaxis was found: patients with hypertension stage 1 had 7.6+/-4.1 episodes/year, those in stage 2 had 8.0+/-4.0 and in stage 3 the incidence was 8.2+/-3.9 (p=ns). The average SBP for all 36 patients was 154+/-19 mmHg on routine readings and 157+/-22 mmHg on epistaxes episodes (p=ns). No difference was also observed regarding DBP: 104+/-18 mmHg vs. 105+/-18 mmHg (p=ns). In conclusion, epistaxis incidence in hypertensive patients is not associated to hypertension severity. Moreover, BP readings in the setting of epistaxis are similar to readings obtained in routine situations.

Headaches and the treatment of blood pressure: results from a meta-analysis of 94 randomized placebo-controlled trials with 24,000 participants

BACKGROUND

Uncertainty exists over whether blood pressure-lowering drugs prevent headache.

METHODS AND RESULTS

A meta-analysis was carried out of the 94 randomized placebo-controlled trials of 4 different classes of blood pressure-lowering drugs (thiazides, beta-blockers, ACE inhibitors, and angiotensin II receptor antagonists) in fixed doses in which data on headache were reported. There were 17,641 participants who were allocated blood pressure-lowering drugs and 6603 who were allocated placebo. Treatment lowered systolic and diastolic blood pressures by 9.4 and 5.5 mm Hg, respectively, on average. One third fewer people on average reported headache in the treated groups (8.0%) than the placebo groups (12.4%) (odds ratio, 0.67; 95% CI, 0.61 to 0.74; P<0.001). About 1 in 30 treated persons benefited by having headache prevented. The prevalence of headache was reduced (P<0.001) in trials of each of the 4 classes of drugs.

CONCLUSIONS

Our results show that blood pressure-lowering drugs prevent a significant proportion of headaches. That this effect is seen with pharmacologically unrelated classes of drugs indicates that it is likely to be due to the reduction in blood pressure per se, the only recognized action that the drugs have in common. This in turn indicates that high blood pressure is a cause of headache, but this conclusion is not supported by observational studies of blood pressure and headache. The uncertainty over whether high blood pressure causes headache does not, however, detract from the practical benefits of the use of blood pressure-lowering drugs in preventing headaches and cardiovascular disease.