Hypertension (High Blood Pressure) — NZ Condition Guide | KiwiMeds

What is Hypertension (High Blood Pressure)?

Hypertension, or high blood pressure, is when the force of blood pushing against your artery walls is consistently too high. It is one of the most common health conditions in New Zealand, affecting around one in three adults. Blood pressure is measured in two numbers — systolic (the top number, pressure when your heart beats) and diastolic (the bottom number, pressure between beats). A normal blood pressure is around 120/80 mmHg. Hypertension is generally diagnosed when readings are consistently 140/90 mmHg or higher.

Symptoms

High blood pressure is often called a “silent killer” because most people have no symptoms at all, even when blood pressure is dangerously high. That is why regular checking is so important. In some cases, very high blood pressure can cause headaches, dizziness, shortness of breath, chest pain, or nosebleeds — but these are not reliable indicators. The only way to know your blood pressure is to have it checked.

Causes and Risk Factors

In most cases, there is no single identifiable cause — this is called essential or primary hypertension. Risk factors include age (risk increases over 40), family history, being overweight, lack of physical activity, high salt diet, excessive alcohol consumption, smoking, chronic stress, and certain medical conditions including kidney disease and sleep apnoea. Secondary hypertension (caused by an identifiable condition) accounts for around 5–10% of cases.

Diagnosis

High blood pressure is diagnosed by a healthcare professional measuring your blood pressure, usually on more than one occasion before a diagnosis is confirmed. Your GP may use a 24-hour ambulatory blood pressure monitor to get an accurate picture. A GP will also check for underlying causes and assess your overall cardiovascular risk using a tool like the PREDICT-CVD calculator.

Treatment Options in New Zealand

Treatment depends on how high your blood pressure is and your overall cardiovascular risk. Lifestyle changes are always recommended first — reducing salt intake, exercising regularly, losing weight if needed, limiting alcohol, and quitting smoking. If medication is needed, there are many Pharmac-funded options including ACE inhibitors (lisinopril, perindopril), angiotensin receptor blockers (losartan, irbesartan), calcium channel blockers (amlodipine), and thiazide diuretics (bendrofluazide). Most people with hypertension take medication long-term.

NZ-Specific Information

The Heart Foundation of New Zealand provides free resources and support for people with high blood pressure. Blood pressure checks are available at most pharmacies for free or a small fee. Pharmac funds all first-line blood pressure medications at the standard $5 prescription charge. The NZ Green Prescription programme offers free support from a health professional to help you become more active — ask your GP for a referral.

Frequently Asked Questions

Can I stop taking my blood pressure medication? Never stop without talking to your doctor first. Blood pressure medication controls but does not cure hypertension — stopping it usually causes blood pressure to rise again. What is a good target blood pressure? For most people, below 130/80 mmHg is the current NZ guideline target. Your GP will set a personalised target based on your age and other conditions. Does stress cause high blood pressure? Stress can temporarily raise blood pressure, but chronic stress is a contributing factor to sustained hypertension.

Supplements That May Support Management

⚠️ Important: The supplements listed below have varying levels of clinical evidence. They are not a substitute for prescribed medications and should only be considered as adjunctive support under the guidance of a qualified healthcare professional. Always inform your GP or pharmacist before commencing any supplement, as interactions with prescribed medicines are possible.

• Magnesium — Magnesium acts as a natural calcium channel blocker, supporting vascular smooth muscle relaxation. Meta-analyses demonstrate modest but statistically significant reductions in blood pressure with supplementation of 300–400 mg daily, particularly in individuals with deficiency.
• Coenzyme Q10 (CoQ10) — Several randomised controlled trials have demonstrated reductions in systolic blood pressure (mean 11–17 mmHg) with CoQ10 supplementation at 100–200 mg daily. It supports mitochondrial function in vascular endothelium.
• Omega-3 Fatty Acids (EPA/DHA) — High-dose omega-3 supplementation (≥3 g/day EPA+DHA) has demonstrated clinically relevant reductions in blood pressure through vasodilatory prostaglandin production and vascular endothelial modulation.
• Potassium (via food, not supplement unless prescribed) — Adequate dietary potassium intake (3500–4700 mg/day) blunts the pressor effects of sodium and is associated with meaningful reductions in blood pressure. Supplementation should only be undertaken under medical supervision, particularly in those on ACE inhibitors, ARBs, or diuretics.
• Hibiscus (Hibiscus sabdariffa) — Randomised trials have shown that hibiscus tea consumption reduces systolic blood pressure by 6–10 mmHg in people with mild-to-moderate hypertension, likely via ACE inhibitory and antioxidant mechanisms.

Relevant Vaccinations

Individuals living with hypertension (high blood pressure) may benefit from the following vaccinations. Please discuss your vaccination status with your GP or practice nurse, as eligibility and funding through the New Zealand National Immunisation Schedule may apply.

• Influenza (annual) — Acute respiratory infections can transiently elevate blood pressure and increase cardiovascular risk. Annual influenza vaccination is strongly recommended and funded for people with cardiovascular risk conditions in NZ.
• Pneumococcal — Pneumococcal disease can precipitate cardiovascular events in people with existing hypertension. Vaccination is recommended for adults with hypertension and associated cardiovascular risk factors.
• COVID-19 — Hypertension is a recognised risk factor for severe COVID-19 outcomes. Maintaining up-to-date COVID-19 vaccination is recommended.

Dietary Guidance

Evidence-based dietary modifications play a meaningful role in the management of hypertension (high blood pressure). The following foods are generally recommended as part of a balanced, condition-appropriate diet. A referral to a registered dietitian may be beneficial for personalised nutritional planning.

• DASH diet pattern (Dietary Approaches to Stop Hypertension) — The DASH dietary pattern — emphasising fruits, vegetables, whole grains, low-fat dairy, and lean protein — is the most evidence-based dietary intervention for hypertension, reducing systolic BP by 8–14 mmHg in clinical trials.
• Beetroot — Beetroot is naturally rich in inorganic nitrate, which is converted to nitric oxide in the body, promoting vasodilation. Regular consumption (including beetroot juice) has demonstrated acute and sustained reductions in blood pressure.
• Garlic — Allicin and other organosulfur compounds in garlic have demonstrated endothelium-dependent vasodilatory and mild antihypertensive effects in meta-analyses. Aged garlic extract has the strongest evidence base.
• Low-fat dairy (yoghurt, milk) — Calcium and bioactive peptides from dairy products support arterial compliance and modest blood pressure reduction. The DASH diet specifically includes 2–3 servings of low-fat dairy per day.
• Dark chocolate (≥70% cacao) — Flavanols in dark chocolate stimulate nitric oxide production, improving vascular endothelial function. Modest regular consumption (20–30 g/day) has shown small but significant reductions in blood pressure.
• Potassium-rich foods (bananas, potatoes, avocado) — Dietary potassium is the most important nutritional modifier of blood pressure after sodium restriction, counteracting sodium’s vasoconstrictive effects. Note: high potassium intake requires medical supervision in kidney disease or those on certain blood pressure medications.

Related Conditions & Medications

Related medications: Amlodipine, Metoprolol. Related conditions: Type 2 Diabetes, High Cholesterol.