Often called the "silent killer," hypertension causes no symptoms for decades while progressively damaging the heart, kidneys, brain and arteries. It affects about 1 in 3 adults globally. Diet and lifestyle change lower blood pressure meaningfully and are first-line in every major guideline, but most people with established hypertension also need medication, and the two work together rather than as alternatives.
Last updated:
High blood pressure (hypertension) is defined as a consistently elevated blood pressure โฅ130/80 mmHg (2017 ACC/AHA guideline) or โฅ140/90 mmHg (WHO and European guidelines). It represents the sustained state of excess mechanical force on arterial walls, a force that silently erodes cardiovascular health over years.
The heart pumps blood against resistance provided by the arteries. When arterial stiffness increases (from inflammation, plaque buildup or endothelial damage), the heart must pump harder. This creates a vicious cycle: high pressure accelerates arterial damage, which raises resistance further, which raises pressure more.
Most hypertension is "primary" or "essential," meaning there is no single identifiable cause: the risk builds from age, family history, a diet too high in sodium and too low in potassium, excess weight, physical inactivity, tobacco use and too much alcohol, acting together over years20.
<120/80
Optimal cardiovascular risk
โฅ140 / โฅ90
Medication typically required
Hypertension rarely causes obvious symptoms until it's severe, which is why regular measurement matters.
| Symptom | What happens |
|---|---|
| Warning Symptoms (Severe Hypertension) | |
| Headaches | Headaches are an uncommon symptom of high blood pressure rather than a classic one, but frequent headaches are a reason to get your blood pressure checked25. These are medical emergencies when accompanied by visual changes or confusion. |
| Visual Disturbances & Retinopathy | Blurred vision, seeing spots or sudden visual loss from hypertensive retinopathy, damage to the retinal blood vessels. An ophthalmologist can see early hypertensive changes in the retina before they become symptomatic. |
| Chest Pain & Palpitations | In hypertensive crisis (BP >180/120), chest pain, palpitations and shortness of breath indicate cardiac strain. Any chest pain with high BP is an emergency; seek immediate medical care. |
| Nosebleeds (Epistaxis) | Spontaneous nosebleeds from fragile nasal blood vessels under chronic pressure stress, more common in severe or uncontrolled hypertension. Not a reliable sign of high blood pressure on their own, as nosebleeds have many causes, but a reason to have your pressure checked. |
Most high blood pressure has no single cause; it builds from diet, weight, activity, alcohol, age and inherited risk acting together over years20.
| Cause | How It Contributes to High Blood Pressure | What Helps |
|---|---|---|
| Too much sodium, too little potassium | Eating too much sodium raises blood pressure, and so does eating too little potassium20; in the DASH-Sodium trial, each step down in sodium lowered systolic pressure further21 | Cutting processed and restaurant food, and eating more potassium-rich foods, as the diet section describes, with the kidney and medication cautions there |
| Excess weight | Obesity or overweight makes the heart work harder20; across 25 trials, each 2.2 lb (1 kg) lost lowered systolic pressure by about 1 mmHg22 | Gradual weight loss through the food pattern in the diet section and regular activity |
| Alcohol | Drinking too much alcohol raises blood pressure20; in people drinking more than two drinks a day, cutting back lowered it, by about 5.5 mmHg systolic in heavy drinkers who halved their intake23 | Cutting down, as the diet section advises |
| Physical inactivity | Regular activity keeps the heart and blood vessels healthy and may help lower blood pressure20 | Aerobic exercise most days, as in the treatment section |
| Age, family history and diabetes | Blood pressure tends to rise with age and runs in families; about 6 in 10 people with diabetes also have high blood pressure20 | Age and family history cannot be changed, and diabetes needs its own treatment, so have regular checks, with treatment by your clinician when readings stay high |
| Test | What it shows |
|---|---|
| At-Home Monitoring | |
| Home BP Monitoring Protocol | Take readings twice daily (morning before medication, evening after rest) for 7 days. Sit quietly for 5 minutes, use a validated upper-arm cuff, measure twice per session and average. Readings taken outside the clinic are recommended to confirm the diagnosis before treatment starts, and they also reveal "white coat hypertension," pressure that is high only in the clinic26. |
| Tracking Patterns | Note BP in relation to meals, stress, sleep, exercise, alcohol consumption and medication timing. Patterns can suggest what affects your readings and are worth showing your clinician; they cannot establish the cause on their own, and suspected sleep apnea needs a sleep study. |
| Clinical Tests | |
| 24-Hour Ambulatory BP Monitor (ABPM) | Wearable cuff measures BP every 20 to 30 minutes over 24 hours, capturing nocturnal dipping patterns (normal: 10 to 20% BP drop during sleep). Non-dipping is linked to kidney disease, sleep apnea and autonomic dysfunction. The most accurate diagnostic tool available. |
| Metabolic & Inflammatory Panel | Fasting glucose, HbA1c, fasting insulin, lipid panel with particle size (LDL-P), hs-CRP (inflammation marker), uric acid (predicts hypertension risk), kidney function (creatinine, eGFR), urine microalbumin (early kidney damage), thyroid panel, magnesium RBC level. |
| Cardiac & Vascular Assessment | Echocardiogram (checks for left ventricular hypertrophy, the heart enlarging under pressure load), carotid intima-media thickness (CIMT) ultrasound (measures arterial plaque and wall thickening) and ankle-brachial index (peripheral artery disease screening). |
DASH diet, magnesium, CoQ10, berberine, hawthorn, hibiscus, stress reduction
The Dietary Approaches to Stop Hypertension (DASH) diet lowered systolic pressure by about 11 mmHg in people with hypertension in the original trials3, with a smaller effect in people whose pressure was already normal. It prioritizes potassium, magnesium, calcium and fiber while minimizing sodium and refined carbohydrates.
Foods that lower blood pressure, and what to cut
| What to eat or do | Details |
|---|---|
| โ Eat More Of: | |
| Potassium-Rich Foods | Bananas, avocado, sweet potato, spinach, white beans, wild salmon, beet greens. Potassium directly counteracts sodium's BP-raising effects by promoting sodium excretion through the kidneys. The adequate intake is 3,400 mg a day for men and 2,600 mg for women, and food is the way to get there17. If you have kidney disease, ask your clinician before raising potassium, even from food. If you form calcium oxalate kidney stones, keep the spinach and beet greens but eat them alongside a calcium food, which binds the oxalate in the gut before it is absorbed. |
| Fatty Fish (Omega-3 Sources) | Wild salmon, sardines, Atlantic mackerel, herring 3x/week. EPA and DHA reduce vascular inflammation, improve endothelial nitric oxide production and lower triglycerides, all of which reduce hypertension risk and severity. |
| Flavonoid-Rich Berries & Dark Chocolate | Blueberries, strawberries, dark chocolate (>85%). Flavonoids (specifically anthocyanins and epicatechin) improve endothelial function by boosting nitric oxide bioavailability, the key vasodilatory molecule. Randomized trials do not show a significant blood-pressure effect from berry supplementation, with pooled estimates between roughly 0.6 and 2.4 mmHg and confidence intervals crossing zero. Cohort data do link higher anthocyanin intake to lower long-term hypertension risk, which is a different and weaker kind of evidence.14 |
| Garlic & Allium Vegetables | Raw or aged garlic, onions, leeks, chives. Pooled trials of garlic supplements give a systolic reduction of about 8.3 mmHg in adults with high blood pressure7, via NO-mediated vasodilation, ACE inhibition and anti-inflammatory mechanisms. Aged garlic extract is the most studied form. |
| โ Avoid or Reduce: | |
| Excess Sodium | In the DASH-Sodium trial, each step down in sodium lowered systolic pressure further, by 6.7 mmHg in all from the high to the low level on a typical US diet, in people with and without hypertension21. The biggest sources: processed meats, canned soups, restaurant food, bread and cheese. |
| Alcohol | Cutting down lowered blood pressure in people drinking more than two drinks a day, by about 5.5 mmHg systolic in those drinking six or more who halved their intake23. Alcohol raises BP by activating the sympathetic nervous system, disrupting sleep quality and increasing cortisol, all independent hypertensive mechanisms. |
| Sugar & Refined Carbohydrates | Fructose (especially high-fructose corn syrup) raises uric acid, reduces nitric oxide production and drives insulin resistance, all of which elevate BP. |
| Processed & Red Meat | Processed meats (deli meats, sausages, bacon) are simultaneously high in sodium, saturated fat and AGEs (advanced glycation end-products), all of which promote endothelial dysfunction and arterial stiffness. Replace with fatty fish, legumes and poultry. |
Each of the following has been studied for blood pressure, with results ranging from reasonably consistent to conflicting, as noted in each row. Effects are not simply additive. Used alongside diet and lifestyle change, they may contribute to a modest additional reduction. They are not a substitute for prescribed treatment, and no head-to-head comparison with medication supports treating them as one.
| Supplement | What it is for | Typical range | Timing | Notes & cautions |
|---|---|---|---|---|
| Magnesium Glycinate | Magnesium relaxes arterial smooth muscle by blocking calcium-mediated vasoconstriction, reduces sympathetic tone and improves insulin sensitivity. The size of the effect depends heavily on who is studied. A 2025 meta-analysis of 38 randomized trials in 2,709 people found a systolic reduction of about 2.8 mmHg overall, rising to roughly 7.7 mmHg in people already on blood-pressure medication and 6 mmHg in those who were magnesium deficient. An earlier pooled analysis found almost no effect at all, so treat this as modest and population-dependent rather than reliable.4 | Set with your prescriber | With dinner or before bed | Glycinate is usually gentler on the gut than oxide, though any form can loosen stools at higher doses. |
| CoQ10 (Ubiquinol) | An antioxidant that protects endothelial cells from oxidative damage. The evidence here does not support the large reductions often quoted. A Cochrane review found moderate-quality evidence that CoQ10 has no clinically significant effect on blood pressure: systolic −3.7 mmHg with a confidence interval crossing zero. A later GRADE-assessed meta-analysis found about −4.8 mmHg in cardiometabolic disease, rated moderate to very low certainty.5 It remains of interest for people taking statins, which deplete CoQ10, but that is a different question from lowering blood pressure. | Set with your prescriber | With a fat-containing meal, fat required for absorption | Ubiquinol is the reduced form. CoQ10 may interact with some blood thinners and with insulin, so check with your prescriber first if you take either29. |
| Omega-3 Fish Oil (EPA+DHA) | Omega-3s improve endothelial nitric oxide production, reduce vascular inflammation and lower triglycerides. A 2022 meta-analysis of 71 trials found a systolic reduction of about 2.6 mmHg, with larger intakes more effective.6 A real but small effect; useful as part of a pattern rather than on its own. | Set with your prescriber | With meals | Choose a third-party tested, molecularly distilled product. Enteric coating reduces fishy aftertaste. Prescription omega-3 (EPA-only) is used for severe hypertriglyceridemia. At high doses fish oil can have an antiplatelet effect, so tell your prescriber if you take a blood thinner30. In heart trials, fish oil supplements raised the risk of atrial fibrillation, an irregular heartbeat, more so above 1 g a day31, so check this dose with your clinician first. |
| Aged Garlic Extract | Aged garlic contains S-allylcysteine, which has ACE-inhibitory and vasodilatory activity. Pooling 12 trials in 553 adults with high blood pressure gives a systolic reduction of about 8.3 mmHg and diastolic about 5.5 mmHg.7 Single trials have reported larger figures; the pooled estimate is the more reliable number. | Set with your prescriber | With food | Aged form (not raw garlic) has little odor and is the form used in most blood-pressure trials. Garlic supplements may increase the risk of bleeding, so talk to your prescriber first if you take a blood thinner or have surgery planned28. |
| Hawthorn Berry Extract | Hawthorn (Crataegus monogyna) contains proanthocyanidins and vitexin, which dilate peripheral arteries and reduce vascular resistance. Trial evidence for blood pressure specifically is limited and the reported effects are small, on the order of a few mmHg diastolic. Better studied for heart failure symptoms than for hypertension.8 | Set with your prescriber | With meals, divided doses | May enhance the effect of cardiac medications; monitor if on cardiac glycosides or nitrates. |
| Hibiscus Flower Extract | Hibiscus sabdariffa anthocyanins appear to act as natural ACE inhibitors. Meta-analyses report a systolic reduction of roughly 7 to 8.5 mmHg, with the largest effects in those whose blood pressure was highest to begin with. Read the figure with care: heterogeneity between trials is very high, so the true effect is less certain than the headline number suggests.9 | Set with your prescriber | After meals | Deep red tart tea. Avoid if on a thiazide diuretic, possible interaction. |
| Berberine | Berberine activates AMPK, reduces insulin resistance and inhibits ACE activity. The evidence conflicts. A 2022 meta-analysis found a systolic reduction of about 5.5 mmHg10, while a 2025 meta-analysis of placebo-controlled trials found no significant effect on either systolic or diastolic pressure in the three trials that measured it.32 Berberine also interacts with many prescription medicines through CYP3A4 and P-glycoprotein, so it is not a casual addition. | Set with your prescriber | With meals | Evidence for blood pressure conflicts between meta-analyses. Monitor blood glucose; berberine can cause hypoglycemia when combined with diabetes medication. Not for use in pregnancy or breastfeeding. |
| Olive Leaf Extract (OLE) | Oleuropein, the main polyphenol in olive leaf, inhibits ACE and reduces arterial stiffness in laboratory work. Human trials are small and few, so treat any specific blood-pressure figure for olive leaf as provisional.11 | Set with your prescriber | With meals | Choose a standardized extract with โฅ20% oleuropein. Avoid very high doses (over 2 g/day), which may cause GI upset. |
| Potassium (from food or supplement) | Potassium promotes sodium excretion and relaxes vascular smooth muscle. The effect depends on who you are: in people with hypertension, a meaningful increase in intake lowers systolic pressure by roughly 4.5 to 5 mmHg, while in people with normal blood pressure the effect is close to zero. The relationship is also U-shaped, so more is not better and very high intakes can raise pressure again.12 Potassium supplements are dangerous with ACE inhibitors, ARBs, potassium-sparing diuretics or reduced kidney function. Food first, and supplements only with your prescriber. | Food sources first. Any supplement only with your prescriber. | With meals | Do not supplement if you have kidney disease or are on ACE inhibitors/ARBs/potassium-sparing diuretics, risk of hyperkalemia. |
Diet, weight and activity changes and prescribed medication work together, and this is what trials show about the pace for adults with high blood pressure.
Diet change acts quickly: in the DASH-Sodium trial, blood pressure was lower within each 30-day diet period on the DASH pattern and on lower sodium21. Home readings show the trend; never stop or change a blood-pressure medicine on the strength of them without your prescriber.
Call 911 for chest pain that does not go away, pain spreading to the arm, neck, jaw or back, or chest pain with sweating, nausea, lightheadedness or breathlessness, and for any sign of stroke: face drooping, arm weakness or slurred speech. Call 911 too for a severe headache with blurred vision or confusion, or for sudden loss of sight, which can be signs of a stroke25. Get prompt advice for frequent headaches or blurred vision25.
Get new guides in your inbox. Once a month: new condition guides and research updates, including the trials that did not work. Free, no spam, and you can unsubscribe in one click.
High blood pressure is not a life sentence. A comprehensive approach, targeting diet, inflammation, stress and metabolic health, can lower blood pressure meaningfully and, with your prescriber, sometimes allow a lower medication dose.
Each numbered entry below is either a source you can follow or a note setting out what the evidence does and does not support. Both are numbered together so the markers in the text line up.
Last reviewed October 20, 2026. Blood-pressure thresholds follow the ACC/AHA guideline.13 Supplement entries are cross-checked against the NIH National Center for Complementary and Integrative Health and the Linus Pauling Institute Micronutrient Information Center.15 This page is nutrition education, not medical advice, and it does not replace your doctor. If you take blood-pressure medication, do not change or stop it, and do not add a supplement, without speaking to your prescriber. Several of the supplements below interact with common antihypertensives.