Blood pressure is the force of blood pushing against the walls of your arteries with each heartbeat. While it naturally fluctuates throughout the day, consistently low blood pressure, known as chronic hypotension, can be a persistent health concern. When low readings become a regular state, it may indicate that the body’s organs, such as the brain and heart, are not receiving enough blood flow, warranting attention.
Defining Chronic Low Blood Pressure
Low blood pressure, or hypotension, is generally defined as a reading below 90/60 mmHg. The first number, systolic pressure, measures the force when your heart beats and pumps blood, while the second number, diastolic pressure, measures the pressure when your heart rests between beats. A single low reading might not be concerning, as blood pressure naturally varies. Chronic low blood pressure, however, refers to a consistent state where readings remain below this threshold over time.
Some individuals naturally have blood pressure readings lower than 90/60 mmHg without experiencing any negative health effects; for them, this is a normal state. However, low blood pressure becomes a clinical concern when it causes symptoms, indicating that organs might not be receiving adequate blood and oxygen. Even without overt symptoms, a healthcare professional might monitor consistently low readings to rule out underlying conditions.
Recognizing the Symptoms
When blood pressure drops too low, the body’s organs may not receive enough oxygen and nutrients, leading to a variety of symptoms. Dizziness or lightheadedness, especially when standing up quickly, is common due to insufficient blood flow to the brain. Fainting, or syncope, can also occur if blood pressure drops significantly, resulting in temporary loss of consciousness.
Other symptoms include:
Blurred or dimmed vision
Persistent fatigue or weakness, sometimes described as “brain fog”
Nausea or vomiting
Cold, clammy, or pale skin
Heart palpitations
Rapid and shallow breathing
Difficulty concentrating
Underlying Causes
Chronic low blood pressure can stem from various factors, including underlying medical conditions, certain medications, and lifestyle or situational circumstances.
Medical Conditions
Heart problems are frequent contributors, such as an abnormally slow heart rate (bradycardia), heart valve issues, a past heart attack, or heart failure, all of which can reduce the heart’s pumping efficiency. Endocrine problems, like an underactive thyroid (hypothyroidism), adrenal insufficiency, or low blood sugar (hypoglycemia), can also affect blood pressure regulation. Severe dehydration, caused by insufficient fluid intake, vomiting, or diarrhea, significantly reduces blood volume, directly lowering blood pressure.
Significant blood loss from injury or internal bleeding can lead to a sudden and severe drop in blood pressure. Severe infections, particularly those that result in septic shock, can cause blood vessels to widen and blood pressure to fall dangerously low. Nutritional deficiencies, such as a lack of vitamin B12 or folate, can lead to anemia, reducing healthy red blood cells and impacting blood pressure. Prolonged bed rest can weaken the body’s ability to maintain blood pressure, and pregnancy often causes temporary low blood pressure as the circulatory system expands.
Medications
Medications can also induce or worsen low blood pressure. Diuretics, which remove excess fluid, and alpha or beta blockers, used to treat high blood pressure, can both lower blood pressure as a side effect. Drugs prescribed for Parkinson’s disease, some antidepressants, and erectile dysfunction medications can also contribute to hypotension. Painkillers and anti-anxiety medications may also relax blood vessels or reduce blood volume, thereby lowering blood pressure.
Diagnosis and Management
Diagnosing chronic low blood pressure typically involves a comprehensive evaluation by a healthcare professional.
Diagnosis
This often begins with a physical exam and a review of medical history and current medications. Multiple blood pressure readings are taken over time, sometimes including measurements while sitting and standing, to observe for a significant drop when changing positions, characteristic of orthostatic hypotension. Blood tests may be performed to identify underlying conditions such as anemia, low blood sugar, or thyroid disorders.
Further diagnostic tests might include:
An electrocardiogram (ECG), which measures the heart’s electrical activity to detect rhythm abnormalities or signs of a heart attack.
An echocardiogram, which uses sound waves to create images of the heart’s structure and blood flow, helping to identify heart valve problems or heart failure.
A stress test, which assesses heart function during physical exertion.
A Tilt-table test, which evaluates how blood pressure and heart rate respond to changes in body position, mimicking the transition from lying down to standing.
Management
Management strategies for chronic low blood pressure often begin with lifestyle modifications.
Increasing fluid intake is commonly recommended to boost blood volume and prevent dehydration.
Carefully adding salt to the diet, if advised by a doctor, can help raise blood pressure.
Eating smaller, more frequent meals, particularly those lower in carbohydrates, can prevent post-meal blood pressure drops.
Avoiding excessive alcohol, standing up slowly, and wearing compression stockings to improve blood flow from the legs to the heart are other helpful measures.
When lifestyle changes are insufficient, specific medications may be prescribed. Fludrocortisone can help the body retain salt and water, increasing blood volume, while midodrine works by constricting blood vessels to raise blood pressure. These medications are typically reserved for specific cases and require medical supervision. Ultimately, treating the identified underlying condition is often the most effective management strategy for chronic low blood pressure. Consulting a healthcare professional is always recommended for accurate diagnosis and personalized treatment.