Blood pressure, the force of blood against artery walls, serves as a fundamental indicator of cardiovascular health. This measurement reflects how effectively blood circulates throughout the body, delivering oxygen and nutrients to tissues and organs. While blood pressure naturally fluctuates throughout the day, consistently abnormal readings can signal underlying health concerns. Both excessively high and low blood pressure can disrupt body functions, leading to complications if not addressed.
What is High Blood Pressure?
Hypertension occurs when the force of blood against artery walls is consistently elevated. Blood pressure is measured with two numbers: systolic (when the heart beats) and diastolic (between beats). Normal is less than 120/80 mmHg. It is diagnosed when readings are consistently 130/80 mmHg or higher, classified as Stage 1 (130-139/80-89 mmHg) or Stage 2 (140/90 mmHg or higher).
Factors contributing to high blood pressure include genetics and age. Lifestyle factors like a high-sodium diet, lack of physical activity, and obesity are common risk factors. Medical conditions such as kidney disease, diabetes, and sleep apnea can also contribute. Often asymptomatic in early stages, hypertension is known as the “silent killer.”
In severe cases or a hypertensive crisis, symptoms can include severe headache, nosebleeds, or blurred vision. Chest pain, shortness of breath, and dizziness may also occur, indicating an emergency. Unmanaged hypertension can lead to serious long-term problems, including heart attack, stroke, kidney failure, and vision problems.
What is Low Blood Pressure?
Low blood pressure, or hypotension, is generally defined as below 90/60 mmHg, though this can vary. Many have readings below this without symptoms. For others, it can impact daily life and indicate an underlying issue.
Factors causing a drop in blood pressure include dehydration, blood loss, and certain medications (e.g., for high blood pressure or depression). Heart conditions (e.g., irregular rhythms, heart failure) and endocrine problems (e.g., thyroid disorders) can also lead to hypotension. A sudden drop upon standing, called orthostatic hypotension, is common and can be caused by prolonged bed rest or pregnancy.
Symptoms often include dizziness, lightheadedness, and fainting. Blurred vision, nausea, fatigue, or difficulty concentrating may also occur. Severe cases can involve confusion, cold/clammy skin, or rapid, shallow breathing. Critically low blood flow risks include falls from fainting, or shock where organs don’t receive enough oxygen.
How High and Low Blood Pressure Differ
Hypertension and hypotension are opposite ends of the blood pressure spectrum, defined by their numerical ranges. High blood pressure indicates excessive force against artery walls, while low blood pressure reflects insufficient pressure. These ranges guide diagnosis and treatment.
Causes and risk factors for each condition are distinct. Hypertension often develops gradually from chronic lifestyle factors like unhealthy diet, inactivity, and obesity. Low blood pressure is often triggered by acute events like dehydration, blood loss, or medication side effects. Underlying medical conditions can contribute to either, but the specific conditions and mechanisms differ.
Symptoms and health consequences also contrast. High blood pressure is often asymptomatic for years, with symptoms like headaches or vision changes appearing only with severe organ damage. Low blood pressure commonly causes immediate symptoms like dizziness and fainting, which can lead to falls. Long-term hypertension dangers include progressive damage to the heart, brain, and kidneys, potentially leading to heart attack or stroke. For hypotension, the acute concern is insufficient blood flow to organs, which can result in shock or critical organ damage if not addressed quickly.
Management principles also vary. Managing hypertension typically involves long-term lifestyle changes (diet, exercise) and often lifelong medication. Treatment for symptomatic hypotension focuses on addressing the underlying cause, such as rehydration, adjusting medications, or using compression stockings.
When to Consult a Doctor
Seeking medical advice for blood pressure concerns is important. If blood pressure is 180/120 mmHg or higher with severe symptoms like chest pain, sudden vision changes, severe headache, or difficulty speaking, seek immediate emergency medical attention. These indicate a hypertensive crisis, which can lead to stroke or heart attack.
For low blood pressure, prompt medical evaluation is crucial if readings fall below 90/60 mmHg with severe symptoms like confusion, loss of consciousness, or cold/clammy skin. These signs might indicate shock or other life-threatening conditions. Do not attempt to self-diagnose severe low blood pressure at home.
Even in non-urgent scenarios, consult a doctor. Schedule a visit if you consistently have high readings at home (even without symptoms) or frequently experience concerning low blood pressure symptoms like recurrent dizziness or fainting. Discuss any new symptoms or potential medication side effects with your healthcare provider. Regular blood pressure check-ups are recommended for monitoring and early detection.