Introduction Hypertension is a major risk factor for cardiovascular disease. World Health Organization (WHO) stated that hypertension affects 1.28 billion of the population globally, with high prevalence in Malaysia. Effective management is crucial for reducing complications, yet inadequate patients’ knowledge may hinder treatment adherence. Therefore, this study aimed to assess the level of knowledge on hypertension and its relationship with socio-demographic characteristics among adult hypertensive patients in Sabah Heart Centre.

Methods A descriptive, cross-sectional study was conducted to assess the level of knowledge on hypertension among 114 adult hypertensive patients. Data was collected using self-administered questionnaire and analysed using SPSS version 26.0. One-way ANOVA test, independent T-test, and Chi-Square Test were used to determine the relationship between participants’ socio-demographic characteristics and their level of knowledge on hypertension.

Results The study findings revealed that 45.6% (n=52) of the respondents have poor knowledge, 30.7% (n=35) of them have moderate knowledge, and only 23.7% (n=27) of them have a good level of knowledge. The results also showed that there was a statistically significant relationship between the level of knowledge on hypertension and age (p = 0.001), educational level (p = 0.009), source of information (p = 0.009), and race (p = 0.035). In contrast, no significant relationship was found between the level of knowledge on hypertension and gender.

Discussion This study's results are mostly comparable to previous studies, while some in contrast with other studies. Poor hypertension knowledge, especially its risk factors, signs and symptoms, complications, and preventive measures, is alarming. Tailored educational strategies are suggested for effectively improving hypertension knowledge among specific groups.

Conclusion The results of this study highlighted the inadequate knowledge of hypertension among patients, which may affect timely diagnosis and management. This may increase the risk of serious complications like heart disease and stroke, leading to poorer health outcomes and higher healthcare costs. Targeted educational strategies, public health campaigns, and healthcare provider training should be focused on improving outcomes and reducing disparities in hypertension care globally.