Causes of high blood pressure (hypertension) 

In most cases, it's not clear exactly what causes high blood pressure (hypertension). But there are several things that can increase your risk.

Who's at risk of high blood pressure?

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

• age – the risk of developing high blood pressure increases as you get older
• a family history of high blood pressure
• being of African or Caribbean origin
• a high amount of salt in your food
• a lack of exercise
• being overweight or obese
• regularly drinking large amounts of alcohol
• smoking
• long-term sleep deprivation

Making healthy lifestyle changes can help keep your blood pressure at a normal level.

Read more about how to prevent high blood pressure.

Known causes of high blood pressure

In about 1 in 20 cases, high blood pressure occurs as the result of an underlying condition, medication or drug.

Conditions that can cause high blood pressure include:

• kidney disease
• diabetes
• long-term kidney infections
• obstructive sleep apnoea – a condition in which the walls of the throat relax and narrow during sleep, interrupting normal breathing
• glomerulonephritis – damage to the tiny filters inside the kidneys
• narrowing of the arteries supplying the kidneys
• hormone problems – such as an underactive thyroid, an overactive thyroid, Cushing's syndrome, acromegaly, increased levels of the hormone aldosterone (hyperaldosteronism) and phaeochromocytoma
• lupus – a condition in which the immune system attacks parts of the body such as the skin, joints and organs
• scleroderma – a condition that causes thickened skin, and sometimes problems with organs and blood vessels

Medicines and drugs that can increase your blood pressure include:

• the combined oral contraceptive pill
• steroid medication
• non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen and naproxen
• some over-the-counter cough and cold remedies
• some herbal remedies – particularly those containing liquorice
• some recreational drugs – such as cocaine and amphetamines
• some selective serotonin-noradrenaline reuptake inhibitor (SSNRI) antidepressants – such as venlafaxine

In these cases, your blood pressure may return to normal once you stop taking the medicine or drug.