Blood pressure

What do the two numbers mean?

Systolic pressure is measured during heart contraction; diastolic pressure is measured between beats. High blood pressure often has no symptoms. 1

Why does blood pressure rise?

Age and family history contribute, alongside salt intake, inactivity and poor sleep. Kidney disease, sleep apnea and thyroid problems can also play a role. Some medicines, including decongestants and anti-inflammatory painkillers, can raise blood pressure: a supplement search alone can miss these causes. 2

Why do repeated measurements matter?

Blood pressure changes during the day. DGE recommends measurements under comparable, quiet conditions. Persistently elevated pressure may require medication as well as lifestyle changes. 1 3

When is a reading urgent?

NHLBI advises immediate contact with a healthcare provider for systolic pressure above 180 mm Hg or diastolic pressure above 120 mm Hg. 1

Can supplements lower blood pressure?

NCCIH finds no supplement with effects comparable to hypertension medicines. 4

GarlicToo little evidence

Small, preliminary or low-quality studies suggest reductions in people with hypertension. The evidence is limited. 4

Fish oilMixed

Randomized trials are mixed, although the overall evidence suggests some blood-pressure benefit. 4

Green tea extractToo little evidence

Research suggests short-term reductions; this is not evidence of equivalence to medication. 4

What matters more than supplements?

DGE emphasizes physical activity, a balanced diet, weight management when appropriate and less salt. Medication is added when lifestyle measures are insufficient or risk is high. 3

What does potassium research show?

A 2020 analysis combined 32 randomized trials lasting at least four weeks, mostly in adults with hypertension. The response was not a simple “more is better” relationship: benefits were greater in people with hypertension and higher sodium intake, while very high intake warranted caution. 5

PotassiumMixed

Trial doses ranged from 30 to 140 mmol daily. The authors found a nonlinear response and limited data at high intakes; the range describes experiments, not a self-treatment plan. 5

Why potassium needs a medication check

Kidney disease, ACE inhibitors, angiotensin receptor blockers and potassium-sparing diuretics can allow potassium to accumulate in the blood. Supplements and potassium-based salt substitutes therefore need individual assessment in people at risk; even ordinary food amounts can be problematic in some of these circumstances. 6

Questions people ask