Many folks are less informed about low blood pressure than they are about high blood pressure.
While low blood pressure typically poses fewer risks, unexpected and substantial drops in blood pressure can occasionally result in serious, even life-threatening complications.
Therefore, it’s beneficial to understand what low blood pressure is, the various types that exist, its causes, symptoms, and common treatments.
And that’s exactly what you’ll learn in this article.
What Is Blood Pressure?
Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It’s one of the primary parameters health professionals use to assess the health of your cardiovascular system.
Blood pressure has two key measurements: systolic and diastolic.
Systolic blood pressure measures the pressure in the arteries when the heart contracts (pumps blood), while diastolic blood pressure measures the pressure when the heart rests between beats.
When we write these numbers, we separate them with a forward slash (/), with the systolic reading to the left and the diastolic reading to the right.
What Is Low Blood Pressure?
Low blood pressure, or hypotension, happens when the force of blood against the arterial walls drops below the normal range.
Unlike high blood pressure, or hypertension, which puts chronic stress on the cardiovascular system, hypotension might not pose significant health risks unless there are noticeable symptoms or underlying health problems.
What Is Considered Low Blood Pressure?
A blood pressure reading below 90/60 mmHg is generally considered low blood pressure.
However, “low” is relative to each individual, as blood pressure ranges can fluctuate depending on age, activity levels, and overall health.
Consequently, doctors typically only diagnose hypotension when low readings accompany noticeable symptoms.
Types of Low Blood Pressure
Low blood pressure doesn’t have a one-size-fits-all definition.
The broad types of low blood pressure—orthostatic, postprandial, neurally mediated, and severe—have unique triggers and manifestations.
Knowing these can help you manage and treat the condition better.
Orthostatic Hypotension
Orthostatic hypotension, also known as “postural hypotension,” occurs when you quickly change from a seated or lying position to standing, causing a sudden drop in blood pressure.
This can cause dizziness or fainting, especially in older adults and those with conditions like Parkinson’s disease and diabetes.
Postprandial Hypotension
Postprandial hypotension occurs after eating.
Digestion demands increased blood flow to the stomach and intestines. In response, your heart rate increases, and your blood vessels constrict to maintain blood pressure.
This mechanism fails in people with postprandial hypotension, leading to a drop in blood pressure and symptoms such as dizziness or fainting.
Neurally Mediated Hypotension
Neurally mediated hypotension (NMH), also known as vasovagal syncope or the “fainting reflex,” happens when there’s a miscommunication between the heart and the autonomic nervous system.
With NMH, prolonged standing causes a decrease in blood pressure that can lead to fainting. NMH most commonly affects children and people experiencing a stressful or emotional event (such as a medical procedure).
Severe Hypotension
Severe hypotension is associated with the life-threatening condition of shock and requires immediate medical intervention.
Potential triggers for severe hypotension include:
- Significant blood loss
- Severe infections
- Severe allergic reactions
- Acute heart issues such as a heart attack or heart failure
What Causes Low Blood Pressure?
A single factor doesn’t cause low blood pressure.
Instead, multiple elements combine to reduce blood pressure.
Here are some common culprits:
- Prolonged bed rest: Being immobile for extended periods can reduce heart function and blood volume, which can lower blood pressure.
- Certain medications: Several drugs can contribute to low blood pressure. For instance, beta-blockers are used to slow heart rate and decrease heart beats, reducing overall blood pressure. Additionally, certain antidepressants can cause hypotension.
- Heart problems: Heart valve problems, bradycardia, heart attack, and heart failure can lower blood pressure by hindering proper circulation.
- Endocrine problems: Disorders such as hypothyroidism and adrenal insufficiency (Addison’s disease) can cause low blood pressure.
- Dehydration: When the body loses more water than it takes in, it can cause weakness, dizziness, and fatigue. Severe dehydration can cause low blood pressure.
- Blood loss: Significant blood loss from a severe injury or internal bleeding can reduce your body’s blood volume and cause a sharp drop in blood pressure.
- Severe infection (septicemia): When an infection in the body enters the bloodstream, it can lead to a life-threatening drop in blood pressure called septic shock.
- Severe allergic reaction (anaphylaxis): Common triggers of this serious and potentially deadly reaction include foods, certain medications, insect venoms, and latex. Anaphylaxis can cause breathing problems, hives, itching, a swollen throat, and a significant drop in blood pressure.
- Nutritional deficiencies: A lack of essential vitamins in the diet can cause conditions that lead to low blood pressure.
What Are Low Blood Pressure Symptoms?
Symptoms of low blood pressure can range from mild to severe and often include dizziness, fainting, blurred vision, fatigue, nausea, and confusion.
In severe cases where hypotension leads to shock, symptoms can intensify to include cold and sweaty skin, rapid breathing, a weak but rapid pulse, and loss of consciousness.
Treatments for Low Blood Pressure
The management of low blood pressure depends on the underlying cause.
If medications, such as beta-blockers, are responsible for the drop in blood pressure, your healthcare provider may revise the dosage or switch to an alternative treatment.
For others, simple lifestyle modifications can be effective.
Including a bit more salt in your diet may help since salt helps retain water and can increase blood pressure. Drinking more water also aids in increasing blood volume, which in turn can elevate blood pressure.
Wearing compression stockings typically used to alleviate varicose veins or prevent deep vein thrombosis can also be useful for some individuals. These stockings help by enhancing circulation and preventing blood from pooling in the lower extremities.
In some cases, a doctor may prescribe medications to treat low blood pressure. These can include fludrocortisone, which boosts blood volume, or midodrine (Orvaten), which inhibits the dilation of blood vessels.
The most severe cases of hypotension might require hospitalization.
For instance, if severe hypotension stems from heart failure, a heart attack, or a severe infection, these conditions require immediate medical attention to treat low blood pressure and manage the underlying issue.
Scientific References +
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