In most cases, it's not clear exactly what causes high blood pressure. But there are things that can increase your risk.
Things that can increase your risk of getting high blood pressure
You might be more at risk if you:
- are overweight
- eat too much salt and do not eat enough fruit and vegetables
- do not do enough exercise
- drink too much alcohol or coffee (or other caffeine-based drinks)
- do not get much sleep or have disturbed sleep
- are over 65
- have a relative with high blood pressure
- are of black African or black Caribbean descent
- live in a deprived area
Making healthy lifestyle changes can sometimes help reduce your chances of getting high blood pressure and help lower your blood pressure if it's already high.
Known causes of high blood pressure
In about 1 in 20 cases, high blood pressure happens as the result of an underlying health condition or taking a certain medicine.
Health conditions that can cause high blood pressure include:
- kidney disease
- long-term kidney infections
- obstructive sleep apnoea – where 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 that can increase your blood pressure include:
- the contraceptive pill
- non-steroidal anti-inflammatory drugs (NSAIDs) – such as ibuprofen and naproxen
- some pharmacy 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.