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When it’s high blood pressure
For people who were told their blood pressure is high, people who just got a very high reading, and the people beside them. This page passes on, by name, what the National Heart, Lung, and Blood Institute (NHLBI) says: what the two numbers mean, what to do with a very high reading and when it is a 911 call, how to get a true reading at home or at a visit, the habits and the kinds of medicine that bring it down, salt and food, what raises the risk, and high blood pressure in pregnancy. It builds the questions to ask at a visit. Take only what you need today.
A word with a dotted line under it, like this, opens its official definition, quoted from a U.S. government glossary.
Right now
- Call 911 if you have a sudden, severe headache, difficulty breathing, a sudden, severe pain in your abdomen, chest or back, numbness or weakness, a sudden change in vision, or problems talking. That is NHLBI’s list.
- A reading of 180/120 and no symptoms? NHLBI says to wait 5 minutes and check again. If it is still high, call your healthcare provider. Do not wait to see if it comes down on its own.
- Pregnant, or just had a baby? NHLBI says a sudden spike above 160/110 is a medical emergency.
- It can also be a heart attack or a stroke: When it might be a heart attack and When it might be a stroke.
- Thinking about ending your life? Call or text 988, at any hour.
More help
- It might be a heart attack or a stroke: When it might be a heart attack and When it might be a stroke.
- Keeping track: Blood pressure log, My medicines and My emergency card.
- Before a visit: Get ready for your appointment.
- No insurance, a medicine or a bill you can’t pay: When you need a doctor and can’t pay, When you can’t afford your medicine and When a medical bill is too much.
- What often comes with it: When blood sugar goes too low or too high, When it’s your kidneys and When it’s heart failure.
- Food, smoking and sleep: When you need food, When you want to quit smoking and Can’t sleep?
- Pregnancy: Pregnant, or with a new baby.
- Looking after someone: When you’re caring for someone.
- All our free tools.
Your heart, blood pressure, blood sugar, thyroid or blood, and not sure this is the right page? The pages on this site for a heart attack or stroke, blood pressure, AFib, heart failure, cholesterol, diabetes and prediabetes, the thyroid, anemia, sickle cell and menopause, on one list.
Other guides on this site that go with this page
Free to read. We chose these ourselves; no professional did. Each guide was written with AI and has not been reviewed by a professional. They are general information, not advice.
- Diabetes, heart disease, and stroke: what raises the risk, the warning signs, the ABCs, and the medicines: diabetes, heart disease and stroke: why diabetes raises the risk, what else adds to it, the warning signs of a heart attack and a stroke, how doctors check your heart, aspirin, statins and the medicines to ask about, and your diabetes ABCs.
- Changing your habits for better health: the four stages, the pros and cons, the roadblocks, and keeping it up: changing your habits for better health (eating better, moving more): the four stages of change, the pros and cons, the common roadblocks and their solutions, small goals, setbacks, and keeping it up.
- Acromegaly: too much growth hormone, the signs, the pituitary tumor, the tests, and the treatment: acromegaly, when the body makes too much growth hormone: what it is, who gets it, the slow changes in the hands, feet and face, what it can lead to, the pituitary tumor behind it, the tests, and surgery, medicines and radiation.
- Cushing’s syndrome: too much cortisol, the signs, steroid medicines, the tests, and the treatment: Cushing’s syndrome, when the body has too much cortisol: what it is, who it affects, the signs and what it can lead to, steroid medicines and tumors as causes, the tests, and surgery, radiation and medicines.
- Diabetes and pregnancy: getting ready, the risks, the blood glucose targets, insulin, and after the baby: diabetes and pregnancy (type 1 or type 2 diabetes, pregnant or planning a pregnancy): getting ready, the risks for the baby and you, the blood glucose targets, insulin and medicines, and after the baby.
- Healthy eating and staying active as you get older: food, fluids, salt, the five kinds of activity, and being good to yourself: healthy eating and staying active as you get older: the foods to have more and less of, fluids, salt, the five kinds of physical activity, staying safe, and being good to yourself.
- Medicines for weight: who they are for, how they work, the seven medicines, side effects, how long, and cost: prescription medicines for weight, such as semaglutide (Wegovy) and tirzepatide (Zepbound): who they are for, how they work, NIDDK’s table of the seven medicines, side effects, how long to take one, and cost.
- Simple kidney cysts: what they are, the symptoms, the tests, and when they need treatment: simple kidney cysts (fluid-filled sacs in the kidneys, often found by chance on a scan): what they are, how common, the rare problems, the scans and lab tests, watching, draining, surgery, and how they differ from PKD.
- Erectile dysfunction (ED): the causes, the tests, and the treatment: erectile dysfunction (ED, trouble getting or keeping an erection): what it is and how common, the causes (medicines included), the visit and the tests, the treatment choices, and what helps prevent it.
- Food portions: portions and servings, how much is enough for you, reading the label, at home, eating out, and on a tight budget: food portions: the difference between a portion and a serving, servings per container, how much is enough for you, reading the Nutrition Facts label, and tips at home, eating out and when money is tight.
- Lupus nephritis: when lupus reaches the kidneys, the signs, the tests, the biopsy, and the treatment: lupus nephritis, kidney disease caused by lupus: what it is, who gets it, the signs (foamy urine, swelling, high blood pressure), what it can lead to, the urine and blood tests, the kidney biopsy, and the medicines, blood pressure and food.
- How the kidneys work: where they are, what they do, the nephrons, and how blood flows through them: how the kidneys work (where they are, what they do, the nephrons, the glomerulus and the tubule, and how blood flows through them): the wastes, the balance of water, salts and minerals, the hormones, the numbers in a day, and the words in plain language.
- Diabetic kidney disease: what it is, who is more likely, the yearly tests, blood sugar and blood pressure goals, and the medicines: diabetic kidney disease: what it is and how diabetes causes it; why it is often silent; what raises the chances; the yearly urine albumin and blood tests; the A1C and blood pressure goals; ACE inhibitors and ARBs; healthy habits and stress; and whether it gets worse.
- High blood pressure and kidney disease: what it does to the kidneys, who is more likely, the numbers and tests, the medicines, and everyday steps: high blood pressure and kidney disease: how high blood pressure harms the kidneys and how damaged kidneys raise it more; how common both are; who is more likely; the symptoms; the two blood pressure numbers and the GFR and urine albumin tests; ACE inhibitors, ARBs and diuretics; sodium, DASH and protein; and activity, weight, smoking, alcohol and stress.
- Medicines and your kidneys: the blood pressure medicines, your pharmacist and your list, NSAIDs, and a plan for sick days: medicines and your kidneys: how to tell an ACE inhibitor (-pril), an ARB (-sartan) and a water pill; one pharmacy and one up-to-date list; NSAIDs in pain, fever and cold medicines; the questions to ask before you get sick; and why being dehydrated changes things.
- Renal artery stenosis: the narrowed kidney artery, high blood pressure that will not come down, the tests, the medicines, stents and surgery, and food: renal artery stenosis: the narrowed kidney artery and renovascular hypertension; its causes (atherosclerosis, fibromuscular dysplasia); who is more likely; the signs; what it can lead to; the tests; medicines, stents and surgery; and food.
This page and its wording were written with AI (Claude) for Scarlet Beast (our AI policy). No doctor, nurse, pharmacist or person living with high blood pressure has reviewed it. The facts were read on October 8, 2026 on the websites of the National Heart, Lung, and Blood Institute, part of the National Institutes of Health (nhlbi.nih.gov: its high blood pressure pages on what it is and symptoms, dated April 25, 2024; diagnosis, dated June 26, 2025; and causes and risk factors, treatment, living with it, and pregnancy, dated April 30, 2024), and on October 9, 2026 on its DASH Eating Plan page (dated February 25, 2026). Changed on October 9, 2026: this page used to pass on two more articles, from a publisher that does not allow its text to be reused this way. We stopped relying on them. The sodium limits and the list of foods now come from NHLBI’s DASH Eating Plan page, and we took out what we could not find in the sources we do use: a description of one dangerous form of very high blood pressure, five tips on home monitors and where to be measured, when medicine is usually started at each level, a weekly amount of exercise, a daily limit on alcohol, the names “essential” and “secondary” hypertension, and several added causes, medicines and tests. The caution about potassium and salt substitutes is now marked as ours. The page says whose words it is passing on, and what is marked “ours” is our own. What we left out or did not read: every medicine brand and amount, the names of the medicines NHLBI lists for pregnancy, side effects (the pages we read list none), blood pressure tables for children, where to get a free reading or a low-cost monitor, prices, and anything about what Medicare, Medicaid or private insurance pay for. We left out the DASH plan’s tables of servings. We did not read the other pages NHLBI links to: its tips to reduce salt and sodium, its fact sheet on measuring your own blood pressure, its wallet card, or its list of approved home devices. The sodium figures are the DASH eating plan’s general ones: your provider’s numbers come first. We called no number. It saves nothing and loads no tracking.