In most people, the causes of high blood pressure are complex. As well as increasing age, genetic factors (such as having a family history of hypertension) and ethnicity (particularly being of Black African and Black Caribbean origin) are associated with increased risk of high BP.
Modifiable causes:
Lifestyle factors are also important. These include:
- Being overweight or obese – more than a quarter of UK adults are obese and more than a 60% are obese or overweight.3
- Excess dietary salt – the average UK salt intake is about 8g/day (compared with a recommended limit of less than 6g/day).4 On average, only about a quarter of the salt we eat is added at the table or in cooking, the majority coming from processed food and food eaten outside the home.
- Diets lacking fresh fruit and vegetables.
- Excess alcohol consumption – heavy drinking, including binge drinking, is associated with increased risk of high BP.
- Physical exercise – lack of exercise is associated with increased risk of high BP. As a nation, we have become less physically active over the last few decades. Current recommendations are that we should be doing at least 150 minutes of moderate physical activity each week5 but only 67% of men and 55% of women achieve this. Recent evidence suggests that exercise levels have fallen still further during lockdown due to COVID-19.
Secondary hypertension
Relatively rarely a specific cause of high blood pressure can be identified, so-called ‘secondary hypertension’. Overall, these causes probably account for fewer than 10% of cases, but they are relatively more frequent among younger people with high blood pressure. Such causes include certain rare genetic causes, kidney disease, an excess of certain hormones that usually regulate BP (such as aldosterone, adrenaline or noradrenaline), narrowing of blood vessels (such as the aorta or the arteries to the kidney) and obstructive sleep apnoea (repeated interruptions to breathing while asleep).
While relatively infrequent, identification of these causes is important as they may require specific different forms of treatment and, in some cases, are potentially curable by surgical intervention or procedures.
