Know when to use urgent NHS care
Use NHS 111 for frequent headaches or blurred vision, chest pain that comes and goes, or other symptoms that worry you. Call 999 for chest pain that does not go away, pain that spreads to your arm, neck, jaw, stomach or back, or chest pain with sweating, sickness, light-headedness or shortness of breath. Do not drive yourself to A&E.[1]
What high blood pressure means
Blood pressure measures the pressure of blood in the arteries. It is written as two numbers. The first is systolic pressure, when the heart pumps. The second is diastolic pressure, when the heart relaxes between beats. Blood pressure changes through the day, so one reading needs context.[1] [3]
The NHS says a measurement taken by a health professional of 140/90 mmHg or higher, or a home reading of 135/85 mmHg or higher, is usually considered high. NICE uses a combination of clinic readings and ambulatory or home averages to confirm a diagnosis. These thresholds guide assessment; they do not replace individual medical advice.[1] [2]
Symptoms and why measurement matters
Most people with high blood pressure feel well. The NHS lists headaches, blurred vision and chest pain as symptoms that can rarely occur, but symptoms cannot confirm or rule out high blood pressure. Arrange a blood-pressure check if you think you may be at risk, or if you are aged 40 or over and have not had one in more than five years.[1]
An unexpectedly raised home reading deserves measured follow-up, not self-diagnosis. Record the reading, the time, what you were doing and any symptoms. Ask a clinician how and when to repeat it. Use NHS 111 or 999 if the urgent symptoms above apply.
Factors that can increase risk
Often there is no single cause. The NHS and BHF describe factors and conditions that can make high blood pressure more likely. They do not identify the reason for an individual’s reading without an assessment.[1] [3]
| Area to consider | Examples |
|---|---|
| Personal and family factors | Blood pressure risk rises with age and may be higher when close relatives have high blood pressure. The NHS also identifies higher risk in people from Black African, Black Caribbean or South Asian backgrounds. |
| Lifestyle factors | A diet high in salt, overweight, smoking, alcohol and long-term stress can increase the chance of high blood pressure. |
| Health conditions and medicines | Kidney disease, diabetes and sleep apnoea can contribute in some people. Some prescribed, over-the-counter or herbal medicines may also affect blood pressure. |
How high blood pressure is confirmed
NICE recommends a structured confirmation process. If a clinic reading is 140/90 mmHg or higher, the clinician repeats it in the consultation. For readings from 140/90 to 180/120 mmHg, NICE recommends ambulatory blood-pressure monitoring where appropriate. Home monitoring is used if ambulatory monitoring is unsuitable or cannot be tolerated.[2]
| Part of the pathway | NICE guidance |
|---|---|
| Repeat clinic measurement | NICE advises a second clinic measurement if the first is 140/90 mmHg or higher, with a third if the second differs substantially. |
| Ambulatory monitoring | For a clinic reading from 140/90 to 180/120 mmHg, NICE recommends ambulatory monitoring to confirm a diagnosis where appropriate. |
| Home monitoring | If ambulatory monitoring is unsuitable or not tolerated, NICE recommends home monitoring for confirmation. |
| Cardiovascular-risk and organ-damage assessment | For diagnosed hypertension, NICE includes urine testing, selected blood tests, an eye examination and a 12-lead ECG within its assessment recommendations. |
NICE confirms hypertension with a clinic blood pressure of 140/90 mmHg or more and a daytime ambulatory average or home-monitoring average of 135/85 mmHg or more. Proper technique, a validated device and the context of each reading matter.[2]
Assessment after a diagnosis
High blood pressure can place extra strain on the heart, blood vessels, brain, kidneys and eyes. NICE recommends assessing cardiovascular risk and looking for target-organ damage after hypertension is diagnosed. Its assessment recommendations include a urine test, a blood sample for HbA1c, electrolytes, kidney function and cholesterol, an eye examination and a 12-lead ECG.[1] [2]
A clinician may select other tests if your history or examination raises a particular question. An ECG records electrical activity; an echocardiogram assesses heart structure and function. Neither test alone confirms the cause of high blood pressure.
Treatment and prevention decisions
NICE advises lifestyle support for people with suspected or diagnosed hypertension. This can include discussion of diet, physical activity, alcohol, smoking and salt intake. Medicines may also be discussed, depending on confirmed pressure, cardiovascular risk, age, health conditions and your preferences. Your clinician should explain the expected benefits and risks of options that apply to you.[1] [2]
Use your readings well
Bring an accurate record of home or ambulatory readings to the appointment rather than relying on a single figure.
Discuss your wider health
Mention kidney disease, diabetes, pregnancy, sleep symptoms, medicines and relevant family history.
Agree a plan
Ask how your blood pressure will be monitored, what support is available and when to seek advice sooner.
Avoid self-adjustment
Do not start, stop or change prescribed blood-pressure medicine without speaking to the clinician responsible for your care.
Booking and related information
The clinic confirms the appropriate appointment route, suitability, availability, preparation, reporting and follow-up arrangements at booking. Private care is not a substitute for urgent NHS care. You may also wish to read about cholesterol numbers, heart palpitations, blood-test services and private GP appointments.
Cardiology services
Explore cardiology appointment pathways and test information.
ECG versus echocardiogram
Understand the different questions that these heart tests can address.
Blood tests at 40
Read about health-check and test-selection context in midlife.
NHS waiting times and private care
Compare care routes while retaining clear urgent-care signposting.
Frequently asked questions
Does high blood pressure cause symptoms?
Usually, no. The NHS says most people do not have symptoms, which is why a blood-pressure measurement is the only reliable way to find out whether it is raised.
Can one high reading diagnose hypertension?
No. A single reading can be affected by many factors. NICE uses repeat clinic readings and usually ambulatory or home monitoring to confirm hypertension in the relevant clinic-reading range.
When should I get my blood pressure checked?
The NHS advises a check if you think you may be at risk, or if you are aged 40 or over and have not had a blood-pressure check in more than five years. Your own clinician may advise a different schedule based on your health.
What tests may be offered after hypertension is diagnosed?
NICE recommends a cardiovascular-risk and target-organ assessment. This can include urine testing, selected blood tests, an eye examination and a 12-lead ECG. A clinician decides what is appropriate for you.
Will lifestyle changes be enough?
Lifestyle support is recommended for suspected or diagnosed hypertension. Whether medicines are also discussed depends on confirmed blood pressure, cardiovascular risk, health conditions, age and your preferences.
References
- [1] NHS. High blood pressure. Last reviewed 19 July 2024. Accessed 30 August 2026. View source
- [2] NICE. Hypertension in adults: diagnosis and management. NICE guideline NG136. Last updated 26 February 2026. Accessed 30 August 2026. View source
- [3] British Heart Foundation. High blood pressure: causes and symptoms. Updated 31 March 2026. Accessed 30 August 2026. View source