High Blood Pressure Symptoms: Warning Signs and When to Call 911
Medically reviewed by Sabeen Munib M.D.
High blood pressure usually causes no symptoms, which is why regular checks matter. Symptoms such as a severe headache, chest pain, shortness of breath, vision changes or confusion usually mean blood pressure is dangerously high. A reading of 180/120 or higher with any of these needs a 911 call.
Does high blood pressure have symptoms?
High blood pressure usually has no symptoms, even when it has been high for years. That is why it is called the silent killer. Most people feel completely normal and only find out when their blood pressure is checked at a doctor's office, a pharmacy or at home.
Nearly 1 in 2 US adults has high blood pressure. Many people believe headaches, nosebleeds, a red face, dizziness or feeling nervous are signs of high blood pressure. These are not reliable warning signs. Some people do get them, but most people with high blood pressure never do, and many people with these symptoms have normal readings. The only way to know your numbers is to measure them.
What can high blood pressure feel like?
When symptoms do appear, it is often because blood pressure is very high, often 180/120 or more, or has started to affect the heart, brain, eyes or kidneys. Signs can include:
- A severe headache, unlike your usual headaches
- Chest pain or pressure
- Shortness of breath
- Blurred vision or other vision changes
- Confusion, trouble speaking or weakness on one side
- Nausea or vomiting with a pounding headache
What blood pressure is dangerously high?
A reading of 180/120 mm Hg or higher is dangerously high and is called severe hypertension. What to do depends on whether you have symptoms.
Call 911 if your reading is 180/120 or higher and you have:
- Chest pain
- Shortness of breath
- Back pain
- Numbness or weakness in the face, arm or leg
- Change in vision
- Difficulty speaking
- A sudden, severe headache or confusion
These can be signs of a hypertensive emergency, when very high pressure is damaging organs within minutes to hours, or of a heart attack or stroke. Do not wait to see if the symptoms go away, and do not drive yourself to the hospital.
If you have no symptoms
Wait 5 minutes, sit quietly and check again. If the second reading is still 180/120 or higher, call your doctor the same day. Do not take extra doses of your blood pressure medicine unless your doctor has told you to.
What are the blood pressure categories?
A blood pressure reading has 2 numbers, written as top over bottom, such as 118/76. The top number (systolic) is the pressure when your heart beats. The bottom number (diastolic) is the pressure when your heart rests between beats. For adults, the current categories are:
- Normal: below 120 and below 80
- Elevated: 120 to 129 and below 80
- Stage 1 hypertension: 130 to 139 or 80 to 89
- Stage 2 hypertension: 140 or higher or 90 or higher
- Severe hypertension: 180 or higher or 120 or higher
Only one number needs to be high to put you in a higher category. For most adults, the treatment goal is below 130/80, and lower is often better when it can be reached safely. These cutoffs are the same for adults of every age. Children and teens are measured against charts for their age, sex and height.
Hypertension is the medical name for high blood pressure. The two terms mean the same thing.
How do you know if you have high blood pressure?
You know you have high blood pressure only by measuring it, usually with readings taken on 2 or more occasions. One high reading at the office is not enough. Stress, rushing or the visit itself can raise the number, which is often called white coat hypertension. Some people have the opposite problem: normal readings at the office but high readings at home.
That is why home readings are now an important part of diagnosis. Adults should have their blood pressure checked at least once a year, and more often if it is elevated or you have risk factors.
How should I check my blood pressure at home?
A home blood pressure monitor gives a truer picture of your everyday numbers than a single office visit. To get accurate readings:
- Use an automatic upper-arm cuff that has been validated for accuracy. Wrist cuffs and smartwatches are less reliable.
- Make sure the cuff fits. A cuff that is too small gives falsely high readings.
- Avoid caffeine, exercise and smoking for 30 minutes before measuring, and empty your bladder.
- Sit quietly for 5 minutes with your back supported, feet flat on the floor and legs uncrossed.
- Rest your arm on a table at heart level, with the cuff on bare skin.
- Take 2 readings 1 minute apart, in the morning before medicines and again in the evening.
- Write down or save every reading, and bring your log and your monitor to your visit.
Measuring twice a day for 1 week before a visit gives your doctor a clear average to work with.
What causes high blood pressure?
For most adults, high blood pressure develops slowly over many years without one single cause. This is called primary hypertension. Common risk factors include:
- Age, since blood vessels stiffen over time
- Family history of high blood pressure
- Extra weight
- A diet high in salt (sodium) and low in potassium
- Drinking alcohol
- Low physical activity
- Smoking and poor sleep
- Diabetes and metabolic syndrome
- Black (African American) background, where high blood pressure is more common and starts earlier
Medical causes (secondary hypertension)
In up to 1 in 10 people with high blood pressure, another condition is driving the pressure up. This is more likely when high blood pressure starts young, starts suddenly or is hard to control. Causes include:
- Kidney disease
- Sleep apnea
- Hormone problems, such as too much aldosterone from the adrenal glands or thyroid disease
- Medicines such as pain relievers like ibuprofen and naproxen, decongestants, some birth control pills, steroids and stimulants
- Recreational drugs such as cocaine or amphetamines
What can cause a sudden increase in blood pressure?
Pain, anxiety, caffeine, nicotine, a salty meal, cold medicines with decongestants and missed doses of blood pressure medicine can all push readings up for a few hours. A sudden, large rise with any of the 911 symptoms above needs emergency care.
High blood pressure in women: pregnancy and menopause
Women face some blood pressure risks at specific times of life:
- Birth control pills that contain estrogen can raise blood pressure in some women. Your doctor should check it after you start them.
- Pregnancy: high blood pressure can start after 20 weeks (gestational hypertension) or turn into preeclampsia, which can affect the mother and baby.
- After delivery: preeclampsia can still develop in the first 6 weeks after giving birth.
- Menopause: blood pressure tends to rise after menopause, so readings that were normal in your 40s may not stay normal.
- A past pregnancy with high blood pressure or preeclampsia raises the chance of high blood pressure and heart disease years later. Tell your doctor about it.
During pregnancy or after delivery, call your doctor right away or go to the emergency room for a severe headache, vision changes, pain in the upper right belly, sudden swelling of the face or hands, or trouble breathing. This applies until 6 weeks after delivery.
Women who are already on blood pressure medicine and planning a pregnancy should talk with their doctor 3 to 6 months ahead, because some medicines are not safe in pregnancy.
Why does high blood pressure matter if I feel fine?
Over years, high blood pressure quietly damages blood vessels and the organs they feed. Uncontrolled, it raises the risk of:
- Heart attack and heart failure
- Stroke
- Kidney disease
- Vision loss
- Memory problems and dementia
Bringing blood pressure down lowers these risks, which is why treating it matters even when you have no symptoms.
How can I lower my blood pressure?
Lifestyle changes lower blood pressure for most people, and they help whether or not you also take medicine. Blood pressure often starts to improve within a few weeks.
- Cut back on salt to less than 1,500 mg a day if you can. Most sodium comes from packaged foods, restaurant meals, bread, deli meats, canned soups and pizza. Even cutting 1,000 mg a day helps.
- Eat potassium-rich foods every day, such as vegetables, fruit, beans and yogurt, unless you have kidney disease or your doctor has told you to limit potassium.
- Follow a DASH-style diet: vegetables, fruit, whole grains, low-fat dairy, fish, beans and nuts.
- If you carry extra weight, losing even 5 to 10 pounds can lower your numbers.
- Get regular exercise: at least 150 minutes a week of moderate activity such as brisk walking.
- Limit alcohol. Less is better, and none is best for blood pressure.
- Quit smoking and aim for 7 to 9 hours of sleep.
Learn how preventive care visits help catch high blood pressure early
When do you need medicine for high blood pressure?
Whether you need medicine depends on your blood pressure category and your overall heart risk. In general:
- Stage 2 (140/90 or higher): medicine is usually started along with lifestyle changes. Many people start with 2 medicines combined in 1 pill.
- Stage 1 (130 to 139 or 80 to 89) with diabetes, kidney disease, heart disease or a higher 10-year heart risk: medicine is usually recommended.
- Stage 1 with low heart risk: lifestyle changes first, with a recheck in 3 to 6 months. Medicine is added if you are not below 130/80.
- Elevated (120 to 129): lifestyle changes, not medicine.
The 4 common first medicine groups are thiazide-type diuretics, ACE inhibitors, angiotensin receptor blockers (ARBs) and calcium channel blockers. The right choice depends on your other conditions, such as diabetes, kidney disease or pregnancy plans. Most people need to keep taking blood pressure medicine to keep the benefit, so do not stop it on your own.
How Dr. Munib approaches high blood pressure
Dr. Munib starts by confirming the diagnosis and looking for anything that may be driving it. At a visit she may:
- Recheck your blood pressure properly and review your home readings
- Order blood tests for kidney function, potassium, blood sugar (A1C) and cholesterol, plus a urine test for protein
- Review your medicines and supplements for anything that raises blood pressure
- Ask about snoring, alcohol, salt and stress
- Estimate your overall heart risk
The plan depends on your readings, your labs and your heart risk. For many people it starts with diet, activity and home monitoring and a recheck in 3 to 6 months. For others it includes a medicine discussion right away. Follow-up visits continue until your readings are at goal.
Learn how Dr. Munib manages high blood pressure and other chronic conditions
Read about metabolic syndrome, which often comes with high blood pressure
Get your blood pressure checked in Irvine
If your readings at home or at a pharmacy are 130/80 or higher, Dr. Munib can confirm the numbers and build a plan with you at our office at 114 Pacifica, Suite 280, Irvine. We are in-network with most PPO plans. Cash-pay visits are $190 for new patients and $150 for returning patients, and labs are billed separately. Call (949) 647-5234 or book online.