Usually there are no symptoms
Most people with high blood pressure feel completely well. That’s why it often goes undetected for years — and why the only reliable way to know is to measure it. Many adults are advised to have it checked at least every few years.
Possible signs when it is very high
With very high readings some people notice headaches, blurred vision, chest pain, shortness of breath, nosebleeds or a pounding feeling in the chest, neck or ears. These aren’t reliable early warnings — they tend to appear only when pressure is dangerously high.
What counts as high?
Broadly, a reading consistently at or above 140/90 mmHg (or 135/85 at home) is considered high. Around 120/80 mmHg is ideal. One high reading isn’t a diagnosis — it’s the pattern over time that matters.
When it’s an emergency
Seek emergency care if a reading is 180/120 mmHg or higher together with chest pain, breathlessness, weakness, difficulty speaking, or vision changes — this can signal a hypertensive crisis.