High Blood Pressure: risk factors
Risk factors for high blood pressure (hypertension) include both modifiable and unmodifiable factors. Modifiable risk factors can be managed within the course of an individual’s life, or at the population level through targeted policy. Risk factors in this section were reviewed by the National Institute for Health and Care Excellence (NICE) and Leung et al (2019).
Unmodifiable Risk Factors
Unmodifiable risk factors for hypertension include:
- Sex and age – NICE estimates the condition to be more common in men under the age of 65 and more common in women in older age groups. The female sex hormone oestrogen is thought to protect against hypertension; therefore, its withdrawal during and after menopause may contribute to increased risk in older women (Connelly et al., 2022).
- Ethnicity - those of black African and black Caribbean origin are most likely to be diagnosed with hypertension.
- Genetic factors - a genetic linkage study by Manosroi & Williams (2019) identified 18 genes that potentially accounted for 50% of primary hypertensives (those with hypertension not resulting from another condition). More research is needed to replicate these findings and explain the role of the genes in the development of the disease.
Modifiable Risk Factors
Modifiable risk factors for high blood pressure can be broadly categorised into three groups: lifestyle and dietary risk factors, psychosocial and socioeconomic risk factors and concurrent conditions.
Lifestyle and dietary risk factors contribute to hypertension either by causing systemic inflammation which triggers an increase in blood pressure, or by increasing water retention and therefore the volume of the blood, which indirectly increases blood pressure (Patrick et al., 2021). These risk factors can be managed within the course of an individual’s life to prevent onset of high blood pressure. Lifestyle and metabolic risk factors include:
- Excess dietary salt
- Being overweight or obese
- Being physically inactive
- Excess alcohol consumption
- Smoking
Psychosocial risk factors have also been associated with high blood pressure, although their role in the development of the condition can be complex. These risk factors can be targeted by policy aimed at improving health and reducing deprivation in Scotland. Risk factors include:
- Social deprivation – the Scottish Health Survey reports that those in the most deprived quintile have the highest prevalence of heart disease and its risk factors, including high blood pressure. This is likely due to the relationship between the lifestyle and dietary risk factors described above, such as smoking, and deprivation.
- Maternal deprivation – the Scottish Government’s Long-term Monitoring of Health Inequalities report (2022) found that low birthweight was more common in areas of greater deprivation. Low birthweight is in turn associated with onset of hypertension later in life (Kanda et al, 2020).
- Living in cold housing – studies have shown associations between room temperature of lower than 18°C and high blood pressure (Umishio et al., 2023).
- Mental health conditions including anxiety have been associated with hypertension (Lim et al., 2021).
Other co-existing medical conditions can also act as a risk factor for the development of hypertension. These include:
- Diabetes
- Kidney disease
Both diseases cause high blood pressure by damaging the kidneys, which filter waste and extra water from the blood (National Institute of Health (NIH), 2017).
