What is High Blood Pressure?
High blood pressure (hypertension) means the force of blood pushing against your artery walls is consistently too high. Over time this damages arteries and organs — particularly the heart, kidneys, brain and eyes.
It affects around 1 in 3 adults in the US and UK, and most people have no symptoms at all — which is why it's called the silent killer.
Hypertension Stages
| Stage | Systolic (mmHg) | Diastolic (mmHg) | What to do |
|---|---|---|---|
| Normal | Below 120 | Below 80 | Maintain healthy habits |
| Elevated | 120–129 | Below 80 | Lifestyle changes |
| Stage 1 Hypertension | 130–139 | 80–89 | Lifestyle changes + possibly medication |
| Stage 2 Hypertension | 140+ | 90+ | Medication usually required |
| Hypertensive Crisis | 180+ | 120+ | Seek emergency care immediately |
Symptoms of High Blood Pressure
Most people with hypertension feel completely normal. When symptoms do occur, they may include:
- Persistent headache (especially at the back of the head)
- Dizziness or light-headedness
- Visual disturbances or blurred vision
- Nosebleeds
- Shortness of breath at rest
- Chest pain or pressure
Blood Tests Your Doctor Orders for Hypertension
| Test | Why it's ordered |
|---|---|
| eGFR & Creatinine | Hypertension damages the kidneys — this checks how well they're filtering |
| Urine ACR (albumin:creatinine) | Detects early kidney damage (protein leaking into urine) |
| Lipid Profile | High cholesterol commonly accompanies hypertension |
| Fasting Blood Glucose / HbA1c | Diabetes and hypertension frequently occur together |
| Potassium & Sodium | Electrolytes affected by some BP medications (diuretics) |
| Thyroid (TSH) | Underactive thyroid can raise blood pressure |
| Full Blood Count (CBC) | Rules out anaemia as a contributing factor |
| ECG | Checks for heart enlargement or rhythm problems from chronic high BP |
Causes and Risk Factors
Primary (Essential) Hypertension
No single identifiable cause — develops gradually over years. Linked to age, genetics, obesity, high salt diet, inactivity and stress. Accounts for 90–95% of cases.
Secondary Hypertension
Caused by an underlying condition: kidney disease, sleep apnoea, thyroid disorders, adrenal gland tumours (phaeochromocytoma) or certain medications. Treating the cause can normalise blood pressure.
How is Hypertension Treated?
Lifestyle changes (effective for Stage 1 and as an adjunct to medication):
- Reduce sodium (salt) to under 2,300 mg per day
- Follow the DASH diet (fruit, vegetables, whole grains, low-fat dairy)
- Exercise at least 150 minutes per week
- Lose weight if overweight (5–10kg loss can reduce BP by 5–20 mmHg)
- Limit alcohol and stop smoking
- Manage stress with relaxation techniques
Medications your doctor may prescribe include ACE inhibitors, ARBs, calcium channel blockers, beta-blockers and thiazide diuretics — often in combination.