Low Blood Pressure (Hypotension): Symptoms, Causes & Treatment

 

A reading of less than 90/60 mm Hg is considered low blood pressure. Low blood pressure can be caused by a variety of problems. Depending on the cause, different treatments are used. Although fainting and dizziness are signs of low blood pressure, many people do not experience these symptoms. Your prognosis can be affected by the cause.

A cardiovascular disease called hypotension, or low blood pressure, is characterized by abnormally low blood pressure.

When the force of the blood pushing against the artery walls is too low, it is known as low blood pressure. Another name for it is hypotension.

Millimeters of mercury (mm Hg) are used to measure blood pressure. A reading below 90/60 mm Hg is generally considered low blood pressure.

What is low blood pressure?

When your blood pressure is significantly lower than expected, it's known as hypotension or low blood pressure. It can occur as a symptom of a range of conditions or as a condition in and of itself. It might not have any symptoms. When it does, however, you may need medical attention.

Changing the way your body handles fluids: 

• Your kidneys are in charge of maintaining your body's fluid balance. 

• Certain medications that cause your kidneys to retain salt and fluid may help with low blood pressure.

Also Read: Low Blood Pressure Emergency Treatment at Home

Types:

Among all of the types of low blood pressure are:

Postural hypotension is another name for orthostatic hypotension. When standing after sitting or lying down, there is a sharp decrease in blood pressure. Dehydration, prolonged bed rest, pregnancy, specific medical conditions, and certain medications are among the causes. Older adults frequently experience this kind of low blood pressure.

 Postprandial hypotension. Hypotension following a meal. 1  to 2 hours after eating, this drop in blood pressure takes place. Older adults are most likely affected, particularly those with high blood pressure. Additionally, older adults who have Parkinson's disease or other disorders that impact the area of the nervous system that regulates automatic functions like breathing and heart rate are at a higher risk. The autonomic nervous system is the term for this. Postprandial hypotension symptoms may be lessened by making certain lifestyle adjustments. Drink plenty of water, avoid alcohol, and eat small, low-carb meals.

 Neurally mediated hypotension. This is a drop in blood pressure that occurs after prolonged standing. Young adults and children are primarily affected by this type of low blood pressure. It could be a result of heart-brain communication issues.

Multiple system atrophy with Orthostatic hypotension. The autonomic nervous system is impacted by this uncommon disorder. Extremely high blood pressure while in a supine position is associated with multiple system atrophy and orthostatic hypotension. Shy-Drager syndrome was another name for it.

Symptoms:

Symptoms of low blood pressure can include:

• Fading or blurred vision

• Feeling lightheaded or dizzy

• Fainting

• Fatigue

• Trouble concentrating

• Upset stomach

Low blood pressure can be a sign of an underlying medical condition for certain people. This is particularly true when there is a sudden drop in blood pressure or when symptoms of low blood pressure occur.

A sharp drop in blood pressure may be harmful. Even a 20 mm Hg change can cause lightheadedness or fainting. These symptoms might appear, for instance, following a decrease in systolic pressure from 110 mm Hg to 90 mm Hg. Furthermore, large drops can be fatal. Serious bleeding, severe infections, or allergic reactions are some of the causes of these.

Shock is a condition that can result from extremely low blood pressure. Shock symptoms include:

• Confusion, especially in elderly individuals

• Clammy, cold skin

• Pallor is another name for a decrease in skin color

• Shallow, rapid breathing

• Rapid and weak pulse

Causes:

There are various causes of low blood pressure. It can be brought on by certain medical conditions and medication use. Blood pressure is also affected by other factors.

The amount of blood the heart pumps and the amount of artery-level blood flow resistance determine blood pressure. Two numbers are displayed on a blood pressure reading:

The systolic pressure is the top number. The pressure in the arteries during a heart beat is the top number.
Diastolic pressure is the bottom figure. The pressure in the arteries during the intervals between heart rests is indicated by the bottom number.

Healthy blood pressure is classified as normal by the American Heart Association. Typically, normal blood pressure is less than 120/80 mm Hg.

The blood pressure fluctuates during the day. It is dependent upon:

• Body position

• Breathing

• Drinks and food

• Medications

• Physical condition

• Stress

• The time of day

Typically, blood pressure is at its lowest at night and rises sharply when you wake up.

Low blood pressure-causing conditions:

Low blood pressure can result from the following medical conditions:

• Pregnancy. Pregnancy-related changes result in rapid blood vessel expansion. Blood pressure may decrease as a result of the changes. During the first twenty-four weeks of pregnancy, low blood pressure is typical. After giving birth, a person's blood pressure typically reaches its pre-pregnancy level.

• Heart and heart valve conditions. A heart attack, heart failure, heart valve disease, and a slow heart rate called bradycardia can cause low blood pressure.

• Endocrine conditions are another name for hormone-related diseases. Blood pressure may decrease as a result of diseases like Addison's disease that impact specific glands that produce important hormones. Hypoglycemia, or low blood sugar, can also lower blood pressure. Diabetes may also be a factor.

• Dehydration. Blood levels in the body decrease when there is insufficient water in the body. This may result in a decrease in blood pressure. Dehydration can result from fever, vomiting, severe diarrhea, excessive use of diuretics, and strenuous exercise.

• Loss of blood. Significant blood loss also causes a decrease in blood volume, which precipitously lowers blood pressure. Serious blood loss can result from internal bleeding and injuries.

• Severe infection. Septic shock is a potentially fatal drop in blood pressure that can occur when an infection in the body enters the bloodstream. Sepsis is another term for an infection that develops when bacteria enter the bloodstream and spread.

• Severe allergic reaction; anaphylaxis is another name for it. A sharp decline in blood pressure is symptoms of a severe allergic reaction.

• A lack of nutrients. Iron, folate, and vitamin B-12 deficiency can prevent the body from producing enough red blood cells. Low blood pressure can result from anemia, which is a lack of healthy red blood cells.

Risk factors:

Blood pressure can be low in anyone. Among the risk factors for hypotension are:

• Age. Adults over 65 are more likely to experience drops in blood pressure when standing up or after eating. Children and young adults are primarily affected by neuronally mediated hypotension.

• Medication. It is possible for some medications to result in low blood pressure. All medications used to treat high blood pressure fall under this category.

• Certain diseases. Low blood pressure can result from diabetes, Parkinson's disease, and certain heart conditions.

• Illegal drugs or alcohol. These have the potential to increase the risk of low blood pressure.

Complications:

Low blood pressure complications can include:

• Feeling dizzy

• Weakness

• Fainting

• Injury from falls

Damage to the heart and brain can result from extremely low blood pressure because it lowers oxygen levels in the body.

How is a diagnosis of low blood pressure made?

Diagnosing hypotension is simple. All you have to do is take your blood pressure. Determining the cause of your hypotension is a different matter. To determine the cause of your symptoms and whether they pose a risk to you, your healthcare provider will probably perform several tests.

To diagnose low blood pressure, what tests will be performed?

The following tests may be suggested by your provider:

Laboratory testing

• Blood and urine tests can check for any possible issues, such as:

• Diabetes

• Deficiencies in certain vitamins

• Hormone or thyroid problems

• Low levels of iron (anemia)

• Pregnancy (for those capable of getting pregnant).

Imagining

 If medical professionals believe that your hypotension is caused by a heart or lung issue, they will probably use imaging tests to confirm their suspicions.  Among these tests are:

•  X-rays

•  CT scans, or computed tomography

•  MRI stands for magnetic resonance imaging

•  Echocardiogram or other tests based on ultrasound

 Testing for diagnosis

•  These examinations search for particular issues with your heart or other bodily systems

•  EKG or ECG (electrocardiogram)

•  Perform stress tests

•  Orthostatic hypotension can be diagnosed with the tilt table test

What is the treatment for low blood pressure?

Finding the cause of low blood pressure is typically the first step in treating it. Hypotension usually gets better on its own if a healthcare professional treats the underlying cause. For example, blood loss and injury can cause hypotension. As long as the injury is repaired and the lost blood is replaced with a blood transfusion, hypotension will be stopped.

Your doctor may alter your dosage or recommend that you stop taking any medications that have an impact on your blood pressure.

Direct treatment is another option if the cause is still unknown. But only if there is a treatable underlying cause can hypotension be cured.

Which drugs and therapies are employed?

Finding and fixing the underlying cause is the most important thing a healthcare professional can do to treat low blood pressure. Simple intravenous fluids, antibiotics, surgery, or even a heart transplant are all possible forms of treatment. A hospital stay is necessary for certain individuals with low blood pressure.

One of three methods is typically used to treat hypotension directly:

• Increasing blood volume: In this technique, which is also referred to as fluid resuscitation, fluids are infused into your blood. Blood transfusions, plasma, and intravenous (IV) fluids are a few examples.

• Making blood vessels: Some medications have the opposite effect from those that reduce blood pressure by relaxing blood vessels in the body.

• Changing the way your body handles fluids: Your kidneys are in charge of preserving the balance of fluids in your body.  Low blood pressure may be aided by certain medications that cause your kidneys to retain salt and fluid in your body.

Prevention:

 How can my risk of low blood pressure be reduced?

 Generally speaking, there is no way to prevent or lower your risk of hypotension.  The only exception is avoiding situations or behaviors that may cause it, like using drugs recreationally or using herbal remedies or supplements that lower blood pressure.

 You may be able to avoid post-meal low blood pressure by eating smaller meals with fewer carbohydrates.

References:

• Sharma S, Hashmi MF, Bhattacharya PT. Hypotension (https://www.ncbi.nlm.nih.gov/books/NBK499961/). February 19, 2023. In: StatPearls. Treasure Island (FL): StatPearls Publishing; Jan 2023-. Accessed 7/10/2023.

• Low blood pressure. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health-topics/low-blood-pressure. Accessed Feb. 10, 2022.

• Low blood pressure: When blood pressure is too low. American Heart Association. https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure/low-blood-pressure-when-blood-pressure-is-too-low. Accessed Feb. 10, 2022.

• National Heart, Lung, and Blood Institute (U.S.) Low blood pressure (https://www.nhlbi.nih.gov/health-topics/low-blood-pressure). Last revised 3/24/2022. Accessed 7/10/2023.

• Palma JA, et al. Mechanisms, causes, and evaluation of orthostatic hypotension. https://www.uptodate.com/contents/search. Accessed Jan. 24, 2022.

• Ricci F, De Caterina R, Fedorowski A. Orthostatic Hypotension: Epidemiology, Prognosis, and Treatment (https://pubmed.ncbi.nlm.nih.gov/26271068/). J Am Coll Cardiol. 2015 Aug;66(7):848-860. Accessed 7/10/2023.

• Juraschek SP, Daya N, Rawlings AM, et al. Association of History of Dizziness and Long-term Adverse Outcomes With Early vs Later Orthostatic Hypotension Assessment Times in Middle-aged Adults (https://pubmed.ncbi.nlm.nih.gov/28738139/). JAMA Intern Med. 2017 Sep;177(9):1316-1323. Accessed 7/10/2023.

• Orthostatic hypotension. Merck Manual Professional Version. https://www.merckmanuals.com/professional/cardiovascular-disorders/symptoms-of-cardiovascular-disorders/orthostatic-hypotension. Accessed March 3, 2022.

• British Heart Foundation. What causes low blood pressure and what are low blood pressure symptoms? (https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/ask-the-experts/low-blood-pressure) Last revised date not listed. Accessed 7/10/2023.

• Bhatt SP. Therapeutic Approach to the Hypotensive Patient. In: Cydulka RK, Fitch MT, Joing SA, Wang VJ, Cline DM, Ma O, eds. Tintinalli’s Emergency Medicine Manual. 8th ed. McGraw Hill; 2017.

• Understanding blood pressure readings. American Heart Association. https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings. Accessed Feb. 10, 2022.