High Blood Pressure: Which Numbers Are Considered Elevated and Why

The blood pressure monitor produces two numbers separated by a slash, and behind them lies the work of the heart and blood vessels at a specific moment. We explain which values are called elevated, why blood pressure rises, and when a conversation with a doctor should not be postponed.

What Is High Blood Pressure

Blood pressure is the force with which blood presses against the walls of the arteries. At the moment the heart contracts, it is at its maximum: this is the systolic, or upper, number. Between beats the heart relaxes and the pressure falls — this is the diastolic, or lower, number. A reading of 120/80 means a systolic of 120 and a diastolic of 80 mmHg.

The plumbing comparison works almost literally: a pump drives water through pipes, and a pressure gauge shows the force against the walls. If the pump is worn out or the pipes are narrowed, the needle goes up and the load falls on the entire system. In a person, the pump is the heart, the pipes are the vessels, and the pressure gauge is the blood pressure monitor.

High Blood Pressure: What Counts as High

When measured in a medical facility, a pressure of 140/90 mmHg and above is considered elevated; when measured at home, the threshold is lower — 135/85 mmHg and above. Arterial hypertension is a systolic pressure of 140 mmHg and above and, simultaneously or independently, a diastolic pressure of 90 mmHg and above.

Grading: normal — below 120/80; elevated blood pressure — 120–129 with the lower number below 80; first-degree hypertension — 130–139 or 80–89; second degree — 140 and above or 90 and above. Values above 180/120 are regarded as a hypertensive crisis: medical assistance is needed immediately.

Blood pressure is measured on both arms, and the higher value is used. A difference of 10–15 mmHg between the arms may indicate peripheral vascular disease.

Why Blood Pressure Rises: Main Causes

In 90–95% of cases it is essential hypertension, or hypertensive disease: it develops gradually with age. The rest are secondary forms: renal causes account for 3–4% of cases, endocrine for 0.1–0.3%; there are also hemodynamic, neurological, and stress-related forms, reactions to certain substances, and hypertension in pregnancy.

Among the risk factors, WHO names age, sex, a sedentary lifestyle, excess salt, alcohol, smoking, diabetes mellitus, obesity, elevated levels of atherogenic lipids and triglycerides, and heredity. Separately noted are blood pressure elevation associated with hormonal contraceptives and dietary supplements, as well as prolonged stress.

Elevated Blood Pressure in Adolescents

In children and adolescents, the numbers are not compared with the adult scale: the doctor compares the result with the norm for other children of the same age, height, and sex. The same number reads differently in an adolescent and in an adult.

Why Persistently High Blood Pressure Is Dangerous

If blood pressure stays high, the heart pumps under overload, and the vessels, brain, kidneys, and eyes are damaged. The risk of heart disease, heart attack, stroke, heart failure, kidney disease, and vascular dementia increases. Lowering blood pressure even by a small amount reduces these risks.

Scale: by the end of 2020, WHO counted 1.13 billion people with hypertension, about 40% of them are unaware of the disease, and only 10% receive treatment.

How It Is Diagnosed and When a Doctor Is Needed

There are usually no symptoms: a person may not suspect the disease for years. Rarely there is headache, blurred vision, or chest pain. Blood pressure can only be known by measuring it, and the diagnosis is not made from a single result: two or more measurements at different visits are needed, as well as home records or 24-hour monitoring.

The doctor assesses:

• the blood pressure level on repeated measurements in the office and at home;
• the results of 24-hour monitoring;
• risk factors: age, smoking, weight, alcohol, heredity;
• signs of target-organ damage and concomitant conditions.

It makes sense to check blood pressure at a pharmacy or with a doctor if elevated blood pressure is suspected, if risk factors are present, and also for people aged 40 and older who have not measured their blood pressure for more than five years.

An elevated number on the blood pressure monitor is not in itself a reason to call an ambulance. You should call 103 or 112 if sudden pain or discomfort in the chest appears that does not go away and radiates to the arm, neck, jaw, abdomen, or back, or if sweating, nausea, dizziness, or shortness of breath are added to the pain. A blood pressure above 180/120 mmHg requires medical assistance without delay.

This material is for reference: it helps to read the numbers on a blood pressure monitor but does not replace a doctor's consultation — the interpretation of your measurements is provided by a specialist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer