High Blood Pressure: When Is It an Emergency?

Maybe you checked your blood pressure at home or at the pharmacy and the number was far higher than you expected, something like 185/120 or 200/110. The first question is: do I need the ER right now? The answer depends on two things: whether the number stays high after you rest and measure properly, and whether you have any symptoms. This guide explains what the numbers mean, when high blood pressure is a real emergency, and when seeing your own doctor is enough.

What blood pressure is too high?

A blood pressure reading has two numbers. The top number (systolic) is the pressure in your arteries when your heart beats; the bottom number (diastolic) is the pressure between beats. The American Heart Association (AHA) groups adult readings like this:

• Normal: less than 120 and less than 80.
• Elevated: 120–129 and less than 80.
• High blood pressure, stage 1: 130–139 or 80–89.
• High blood pressure, stage 2: 140 or higher, or 90 or higher.
• Severe: higher than 180 and/or higher than 120. This is the AHA's "crisis" threshold.

If your two numbers fall into different groups, the higher group counts. The NHS uses slightly different cut-offs: 140/90 or higher at a clinic, or 135/85 or higher at home, is usually considered high. Either way, a diagnosis is never based on a single reading, but on several readings taken at different times.

Blood pressure 180/120: what should I do right now?

1. First, do you have any of the 911 symptoms listed below? If yes, don't wait and don't recheck. Call 911 now.
2. If you have no symptoms, sit quietly with your back supported and feet on the floor for about five minutes.
3. Measure again, the right way (see the next section).
4. If it is still higher than 180/120 and you have no symptoms, contact your doctor straight away. If you can't reach them, come in to be checked the same day.
5. If symptoms appear at any point, call 911. Don't wait to see whether your blood pressure comes down on its own.

The second reading is often lower after rest, because stress, anxiety, moving around and coffee just before measuring can all push the number up for a while. That is why measuring correctly matters as much as the number itself.

How do I measure my blood pressure correctly?

These steps follow guidance from the US Centers for Disease Control and Prevention (CDC):

• Avoid caffeine, smoking (including shisha), exercise and food for 30 minutes before measuring.
• Empty your bladder first.
• Sit in a chair with your back supported for at least five minutes before the reading.
• Keep both feet flat on the floor and your legs uncrossed.
• Rest your arm on a table at chest height. Put the cuff on bare skin, not over clothing, and make sure it is the right size for your arm.
• Don't talk during the measurement.
• Take at least two readings, 1 to 2 minutes apart, and write them down.

When you see your doctor, bring your monitor and your log of readings. It helps them check that your device is accurate and see your real pattern.

Hypertensive urgency vs emergency: symptoms decide

The number alone doesn't settle it. A reading higher than 180/120 with no symptoms is what the AHA now calls severe hypertension; it used to be called hypertensive urgency. It usually doesn't need a hospital stay, but you should contact a doctor as soon as possible.

The same reading with symptoms that suggest damage to organs, such as the heart, brain, kidneys or eyes, is a hypertensive emergency. Here, every minute matters, and the right place is the emergency department via 911.

When to come in now: the red flags

Call 911 for

• Chest pain or pressure, or pain spreading to the arm, neck, jaw or back.
• Shortness of breath.
• Stroke signs: a drooping face, weakness or numbness in an arm or leg, or trouble speaking.
• A sudden change in vision, loss of vision or double vision.
• Confusion, unusual drowsiness or a seizure.
• A sudden, very severe headache, unlike any you've had before.
• Severe back or abdominal pain with a very high reading.

Go to the ER or come in now for

• Pregnancy after 20 weeks, or the first weeks after birth, with high blood pressure and a headache, blurred vision, pain under the ribs or sudden swelling.
• A very high reading with feeling generally unwell, a headache or a nosebleed, even if the symptoms aren't severe.
• Severe dizziness or feeling faint after a change in blood pressure medicine, or after taking too much by mistake.

Same-day urgent care

• A reading that stays higher than 180/120 after rest and a recheck, with no symptoms, and you can't reach your doctor.
• You've run out of your blood pressure medicine and your readings are higher than usual.
• Headaches or blurred vision that keep happening.

Home care and a routine doctor visit are usually fine

• Readings between 130/80 and 180/120 with no symptoms: log them and book a visit with your doctor.
• A single high reading that came down after rest and a proper recheck.

Chest pain and breathlessness can be a heart attack; read our guide to heart attack warning signs. Weakness on one side or trouble speaking can be a stroke; learn the stroke symptoms and the FAST test. Jordan's emergency number is 911.

What does my reading mean? A quick guide

This table is for adults and is a rough guide, not a substitute for an examination. If you have any of the 911 symptoms, call regardless of the number:

Does high blood pressure cause headaches or nosebleeds?

This is one of the most common myths. Many people say "I know my pressure is up because my head hurts." But the AHA says that in most cases high blood pressure doesn't cause headaches or nosebleeds, and the NHS says it usually causes no symptoms at all. That is why it is called the silent killer: many people have it for years without knowing.

It works the other way too: pain and anxiety raise blood pressure. Someone with a bad headache may find their reading is high because of the pain itself, not because the pressure caused the headache. The important exception is a hypertensive crisis: if your reading is unusually high and you have a headache or nosebleed and feel unwell, rest five minutes and recheck, and if it is still 180/120 or higher, call 911.

To know when a headache itself is a warning sign, read our guide headache: when to worry.

Should I take an extra blood pressure pill?

Don't take an extra dose on your own, and don't take blood pressure medicine prescribed for someone else at home. Bringing pressure down too fast or too far can cause dizziness, fainting or a fall, especially in older people, and can be harmful when a doctor doesn't know what's going on. Keep taking your usual medicine on schedule, and if your readings are high again and again, contact your doctor so they can adjust your treatment.

High blood pressure in pregnancy: when is it urgent?

Pre-eclampsia is a condition where blood pressure rises during pregnancy. It is most likely from 20 weeks onwards, and it can also develop in the days or weeks after birth. Early signs are often unnoticeable, which is why your blood pressure and urine are checked at antenatal visits. But according to the NHS, these symptoms need checking immediately:

• A headache that doesn't ease with ordinary painkillers.
• Blurred vision or seeing flashing lights.
• Pain under the ribs.
• Sudden swelling of the face, hands or feet.
• Heartburn that won't go away with medicine, vomiting, or feeling seriously unwell.

If you are pregnant or have recently given birth and have these symptoms, don't wait for your next appointment. Contact your obstetrician or maternity unit straight away, or go to the ER, and call 911 for a seizure, breathlessness or feeling extremely unwell.

What about low blood pressure?

Low blood pressure without symptoms usually isn't a problem. But dizziness or fainting, especially when standing up, in the heat or after starting a new blood pressure medicine, needs attention. Read our guide to fainting and dizziness: when to go to the ER.

Urgent care or the ER? What happens when you arrive

If your reading is very high but you have no symptoms and can't reach your doctor, urgent care sees walk-ins around the clock. With chest pain, breathlessness, stroke signs, vision changes, confusion or a severe headache, call 911 or go straight to the emergency department. If you're unsure, our guide to ER vs urgent care explains the difference.

The team starts by measuring your blood pressure more than once, then the doctor asks about your symptoms and medicines and examines you. They may order blood or urine tests to look for signs that the kidneys or other organs are affected. Based on the results, the doctor decides whether this can be followed up with your own doctor or needs further assessment or treatment. If you need a test or treatment that isn't available on site, the team will tell you where to go. Bring your medicines, or a list of them, and your log of readings if you have one.

Sources

• American Heart Association — Understanding Blood Pressure Readings
• American Heart Association — When to Call 911 About High Blood Pressure
• CDC — Measuring Your Blood Pressure
• NHS — High Blood Pressure
• NHS — Pre-eclampsia