Nearly half of American adults have high blood pressure, and most of them feel completely fine. That is the problem with it. It does its damage to the heart, kidneys, brain, and eyes for years before anything hurts.
This page covers what causes it, what symptoms it can and cannot cause, and how it is treated. For the full clinical picture, including when to look for a hidden cause, see our hypertension page.
What counts as high blood pressure
Blood pressure is two numbers. The top number (systolic) is the pressure when your heart beats. The bottom number (diastolic) is the pressure between beats.
| Blood pressure (mmHg) | Category |
|---|---|
| Below 120 / 80 | Normal |
| 120–129 / under 80 | Elevated |
| 130–139 / 80–89 | Stage 1 hypertension |
| 140+ / 90+ | Stage 2 hypertension |
| Over 180 / over 120 | Crisis — seek care now |
One reading does not make the diagnosis. Blood pressure moves with stress, caffeine, pain, and a rushed walk from the parking lot. The diagnosis comes from repeated readings, ideally including some taken at home.
What causes high blood pressure
For most people there is no single cause. This is called essential or primary hypertension. It builds slowly from a mix of things:
- Family history
- Age, as arteries stiffen
- Too much salt, which is easy in a diet built on restaurant and packaged food
- Extra weight
- Not enough physical activity
- Heavy drinking
- Poor sleep, especially untreated sleep apnea
For a smaller group, high blood pressure has a specific cause that can be found. This is secondary hypertension. The common ones:
- Kidney disease
- Primary aldosteronism, an adrenal gland making too much of a salt-retaining hormone
- Sleep apnea
- Thyroid disease
- A narrowed artery to a kidney
- Medications: NSAIDs like ibuprofen and naproxen, decongestants, some birth control pills, and stimulants
Secondary hypertension is more likely if your pressure rose suddenly, started before age 30, needs three or more drugs to control, or comes with low potassium. In those cases the cause is worth looking for, because treating it can bring the pressure down for good.
What symptoms does high blood pressure cause?
Usually none. That is the honest answer, and it is why so many people go undiagnosed.
Headaches, nosebleeds, and a flushed face get blamed on blood pressure, but at ordinary high readings they are not reliable signs. The only way to know your blood pressure is to measure it.
Very high pressure is different. A reading over 180/120 with any of the following needs emergency care:
- Chest pain or pressure
- Shortness of breath
- Severe headache with confusion or vision changes
- Weakness or numbness on one side, or trouble speaking
- Blood in the urine or a sudden drop in urine
What high blood pressure does over time
Years of high pressure wear on blood vessels everywhere. The damage shows up as:
- Heart attack and heart failure, which often shows up first as swollen feet and ankles
- Stroke and memory problems
- Chronic kidney disease, which then raises blood pressure further
- Vision loss
- Aneurysms
Bringing the pressure down lowers every one of those risks. The benefit starts as soon as the numbers improve.
How high blood pressure is treated
Lifestyle changes come first and keep working alongside medication:
- Cut salt. Most of it comes from restaurant food, bread, deli meat, and canned soup, not the salt shaker.
- Eat more fruits, vegetables, beans, and whole grains. This is the DASH eating pattern, and it lowers pressure about as much as one medication.
- Move for at least 150 minutes a week.
- Lose weight if you carry extra. Even 10 pounds helps.
- Limit alcohol.
- Get sleep apnea treated if you snore and wake up tired.
Medication is not a last resort. At 140/90 and above, current guidelines start medication alongside lifestyle change. The first-line choices are a thiazide-type diuretic, an ACE inhibitor, an ARB, or a calcium channel blocker, chosen based on your other conditions. Many people need two, and a single pill that combines both is easier to stick with. Beta blockers are good drugs for other problems but are not a first choice for blood pressure alone.
Home monitoring makes treatment work. A validated upper-arm cuff, readings at the same times each day, and a log to bring to visits tell us far more than one number in the exam room.
When to see a specialist
See a nephrologist or hypertension specialist if your blood pressure stays above goal on three medications, rose suddenly, started young, comes with low potassium, or if you already have kidney disease. Learn more about how we approach hypertension and essential hypertension.