Hypertension (High Blood Pressure): Causes, Symptoms, and Treatment

High blood pressure, also known as hypertension (high blood pressure), is one of the most common health conditions worldwide — and one of the most dangerous when left untreated. Often called the “silent killer,” it usually develops without obvious symptoms, but over time it can quietly damage your heart, brain, kidneys, eyes, and other organs. The World Health Organization estimates that over 1.2 billion people between the ages of 30 and 79 are living with hypertension, with two-thirds of them in low- or middle-income countries. In the United States alone, nearly half of all adults have high blood pressure, and many don’t even know it. The good news is that hypertension can be detected through simple blood pressure checks, and in many cases, it can be controlled or even prevented with the right lifestyle changes and medical care.

What Is Hypertension?

Blood pressure is the force of blood pushing against the walls of your arteries as your heart pumps. A blood pressure reading is given as two numbers: the first, or systolic pressure, measures the force when your heart contracts; the second, or diastolic pressure, measures the force when your heart relaxes between beats. Both are measured in millimeters of mercury (mmHg).

A normal reading is generally considered to be below 120/80 mmHg. In the United States, hypertension is diagnosed when your blood pressure is consistently 130/80 mmHg or higher. In the UK and many European countries, the threshold is slightly higher at 140/90 mmHg in a clinical setting. When measured at home, it is 135/85 mmHg. Blood pressure naturally fluctuates throughout the day. A single high reading doesn’t necessarily mean you have hypertension. Doctors usually confirm the diagnosis with repeated measurements taken on different days. Sometimes they use home monitors or 24-hour ambulatory monitoring for a more accurate picture.

Blood Pressure Categories

Healthcare providers classify blood pressure into several categories. Readings below 120/80 mmHg are considered normal. If the top number is between 120 and 129 while the bottom number stays below 80, the reading is described as “elevated.” Stage 1 hypertension begins at 130–139 systolic or 80–89 diastolic, while Stage 2 hypertension starts at 140/90 mmHg or higher. Blood pressure readings above 180/120 mmHg indicate a hypertensive crisis, which is a medical emergency requiring immediate care.

Why Hypertension Is Dangerous

The reason hypertension (high blood pressure) is so concerning is that it damages your arteries over time, making them less elastic and more prone to narrowing, weakening, or rupturing. This process increases your risk of heart attack, stroke, kidney disease, heart failure, vision loss, and even cognitive decline or dementia. The higher your blood pressure, and the longer it remains uncontrolled, the greater your risk of these complications.

Symptoms — Or the Lack of Them

Most people with high blood pressure feel perfectly fine, even when their readings are dangerously high. This is why regular screening is so important. In rare cases, especially if blood pressure rises quickly to very high levels, symptoms such as headaches, dizziness, blurred vision, chest pain, shortness of breath, or nosebleeds may occur. A hypertensive crisis — when blood pressure exceeds 180/120 mmHg — can cause severe symptoms and should be treated as a medical emergency.

Causes and Risk Factors

Hypertension can be classified into two main types. Primary (or essential) hypertension develops gradually over many years, often due to a combination of genetic factors, aging, and lifestyle habits. Secondary hypertension is caused by an underlying condition such as kidney disease, hormonal disorders, obstructive sleep apnea, or the side effects of certain medications.

Some risk factors are beyond your control, such as age, family history, or ethnicity — for example, people of Black African or South Asian heritage are at higher risk. However, many lifestyle factors play a major role. Being overweight, eating a diet high in sodium and low in potassium, drinking too much alcohol, smoking, living a sedentary life, or experiencing chronic stress can all contribute to rising blood pressure. In women, pregnancy and the use of birth control pills can also increase risk, especially if other factors are present.

Diagnosis

Checking your blood pressure is quick, painless, and essential for early detection. Readings are often taken in a clinic using an inflatable cuff, but home monitoring can be helpful, especially for people who experience “white coat hypertension” — elevated readings caused by anxiety in a medical setting. On the other hand, some people have “masked hypertension,” where their clinic readings are normal but home readings are high. For the most accurate assessment, doctors may recommend 24-hour ambulatory monitoring. Alongside blood pressure measurements, your doctor may order blood and urine tests, cholesterol checks, and an electrocardiogram to assess overall cardiovascular health and look for any damage caused by hypertension.

Treatment and Management

For some people, especially those with mildly elevated readings, lifestyle changes can be enough to bring blood pressure back into the healthy range. Eating a balanced diet rich in fruits, vegetables, whole grains, and low-fat dairy — such as the DASH (Dietary Approaches to Stop Hypertension) diet — has been shown to lower blood pressure. Reducing sodium intake to under 1,500 milligrams per day, increasing potassium-rich foods like bananas and leafy greens, maintaining a healthy weight, exercising regularly, limiting alcohol, quitting smoking, and managing stress can all make a significant difference.

If lifestyle changes aren’t enough, or if blood pressure is already in Stage 2 or causing organ damage, medication may be prescribed. Common first-line medicines include ACE inhibitors, angiotensin receptor blockers (ARBs), calcium channel blockers, and diuretics. Sometimes a combination is needed to achieve the target range. Your doctor will choose the medication based on your overall health, other conditions, and how you respond to treatment. It’s important to take medications as prescribed and attend follow-up appointments for monitoring.

Prevention

The best way to prevent hypertension is to adopt heart-healthy habits early in life. Staying physically active, eating a diet low in salt and rich in fresh produce, keeping your weight in check, avoiding tobacco, and limiting alcohol can all help keep your blood pressure in a healthy range. Even if you have a family history, these changes can delay or prevent the onset of high blood pressure.

When to Seek Medical Advice

Adults should have their blood pressure checked at least every two years starting at age 18, and more often after age 40 or if other risk factors are present. Pregnant women and people with conditions like diabetes or kidney disease may need more frequent monitoring. If you ever experience severe headache, chest pain, shortness of breath, vision changes, or any other concerning symptoms alongside a very high reading, seek emergency medical attention immediately.

Hypertension may be silent, but it’s not unstoppable. With regular checks, healthy lifestyle choices, and, when necessary, the right treatment, you can protect your heart, brain, and overall health — and greatly reduce the risks that make this condition so dangerous.