High blood pressure (hypertension) - Causes 

In over 90% of cases, the cause of high blood pressure (hypertension) is unknown but several factors can increase your risk of developing the condition.

Where there is no specific cause, high blood pressure is referred to by doctors as primary high blood pressure (or essential high blood pressure).

Factors that can raise your risk of developing primary high blood pressure include:

• age: the risk of developing high blood pressure increases as you get older
• a family history of high blood pressure (the condition seems to run in families)
• being of African or Caribbean origin
• a high amount of salt in your food
• a lack of exercise
• being overweight
• smoking
• drinking large amounts of alcohol
• stress

Known causes

About 10% of high blood pressure cases are the result of an underlying condition or cause. These cases are referred to as secondary high blood pressure.  

Common causes of secondary high blood pressure include:

• kidney disease
• diabetes
• narrowing of the arteries (large blood vessels) supplying the kidneys
• hormonal conditions, such as Cushing's syndrome (a condition where your body produces an excess of steroid hormones)
• conditions that affect the body’s tissue, such as lupus
• oral contraceptive pill
• painkillers known as nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen
• recreational drugs, such as cocaine, amphetamines and crystal methamphetamine
• herbal remedies, such as herbal supplements

Find out about how to get your blood pressure tested.