What does it mean when your blood pressure drops suddenly

What is hypotension?

Hypotension is abnormally low blood pressure (lower than 90/60 mm Hg). If your blood pressure gets too low, it can cause dizziness, fainting or death.

Low blood pressure is not a condition that is usually treated except if it occurs in the elderly or occurs suddenly. In patients over 65, it could indicate the brain and limbs are not receiving adequate blood supply. If your blood pressure drops suddenly, it could deprive the brain of blood, which can lead to lightheadedness or dizziness.

When blood pressure drops suddenly after moving from a lying down to a sitting position, it is called postural hypotension or orthostatic hypotension.

When blood pressure drops from standing for a long period of time and leads to passing out, it is called vasovagal syncope.

Common related conditions

Causes of hypotension

There are several causes of hypotension including:

• Prolonged bed rest
• Pregnancy
• Low or high body temperature
• Excessive blood loss
• Severe dehydration
• Blood infections such as sepsis
• Anaphylaxis allergic reaction
• Reactions to medication or alcohol

Risk factors for hypotension

• Age — your risk of low pressure increases as you age. Approximately 10-20% of people older than 65 have postural hypotension.
• Medications — medications, such as alpha blockers, can lower blood pressure.
• Other serious conditions — if you have diabetes or Parkinson’s disease, you have a higher risk for developing hypotension.

Symptoms of hypotension

Most doctors don’t consider hypotension serious unless it produces noticeable symptoms such as:

• Nausea
• Fainting
• Dehydration
• Blurred vision
• Cold, clammy, pale skin
• Fatigue
• Depression

If you have cold, clammy or pale skin, rapid or shallow breathing, weak or rapid pulse or confusion, you could be suffering from extreme hypotension, which could lead to death. Call 911 immediately if you suspect you are suffering from extreme hypotension.

Diagnosis of hypotension

One abnormally low blood pressure reading without any other symptoms will usually not cause concern. In most cases, your doctor will monitor you over a series of visits to evaluate if the low blood pressure is a consistent pattern. The physician may also order other diagnostic tests to determine the underlying cause of the condition.

Tests that your doctor may order include:

• Blood tests — can help you determine if you have hypoglycemia (low blood sugar), hyperglycemia/diabetes (high blood sugar) or anemia (low red blood count).
• Electrocardiogram (ECG) — can detect the heart’s electrical signals to detect heart rhythm or structural abnormalities, as well as problems with the supply of oxygen-rich blood to the heart.
• Echocardiogram — can show detailed images of the heart to determine structure and function.
• Stress test — during a stress test, you will do some form of exercise to get your heart pumping faster and then you will be monitored with an echocardiogram or electrocardiogram.
• Tilt table test — will determine how your body reacts to changes in position; you will lie on a table that is then tilted to simulate moving from a lying to standing position.

Treatments of hypotension

Low blood pressure that doesn’t show any symptoms does not typically require treatment. For those who do have symptoms, you will be treated based on what the underlying cause of the low blood pressure is.

Home treatments include:

• Increasing water consumption and limiting alcohol consumption — water helps increase blood volume and prevent dehydration.
• Wearing compression socks — wearing compression socks promotes blood flow in the legs.
• Consuming more salt — sodium makes it harder for your body to rid itself of excess fluid and adds strain to the blood vessels resulting in raised blood pressure.
• Exercising regularly — regular exercise promotes blood flow.

If conservative treatments are not successful in increasing your blood pressure, your doctor may need to prescribe medication.

Drugs that treat hypotension include:

• Fludrocortisone — a drug which helps the body retain sodium in the kidney, which helps raise blood pressure.
• Midodrine — a drug that can increase blood pressure by activating receptors on the small arteries and veins.

Find a cardiologist nearby

Mercy Health locations that can treat you

Blood pressure is the force of blood pushing against the walls of your arteries as the heart pumps blood. It is usually described as two numbers: systolic and diastolic. The numbers record blood pressure in millimeters of mercury (mm Hg), with systolic listed above diastolic.

For most adults, a normal blood pressure is usually less than 120/80 mm Hg. Low blood pressure is blood pressure that is lower than 90/60 mm Hg.

Some people have low blood pressure all the time, and it is normal for them. Other people experience a sudden drop in blood pressure or have low blood pressure that may be linked to a health problem. This can be dangerous, as it could mean your heart, brain, or other vital organs are not getting enough blood flow and you are at risk for a heart attack or stroke.

What causes low blood pressure?

Many systems of the body, including organs, hormones, and nerves, regulate blood pressure. For example, the autonomic nervous system sends the “fight-or-flight” signal that, depending on the situation, tells the heart and other systems in the body to increase or decrease blood pressure. Problems with the autonomic nervous system, such as in Parkinson’s disease, can cause low blood pressure.

Other causes of low blood pressure include:

• Blood loss from an injury that causes a sudden drop in blood pressure
• Dehydration
• Diabetes
• Heart problems such as arrhythmias (irregular heartbeat)
• Medicines to treat high blood pressure, depression, or Parkinson’s
• Pregnancy

Older adults also have a higher risk for symptoms of low blood pressure, such as falling, fainting, or dizziness upon standing up or after a meal. Older adults are more likely to develop low blood pressure as a side effect of medicines taken to control high blood pressure.

What are the symptoms?

For many people, low blood pressure goes unnoticed. Others may feel symptoms such as:

• Confusion
• Dizziness or lightheadedness
• Fainting
• Feeling tired or weak
• Blurry vision
• Headache
• Neck or back pain
• Nausea
• Heart palpitations, or feelings that your heart is skipping a beat, fluttering, or beating too hard or too fast

What should you do if you have symptoms?

Sitting down may relieve the symptoms. If your blood pressure drops too low, your body’s vital organs do not get enough oxygen and nutrients. When this happens, low blood pressure can lead to shock, which requires immediate medical attention. Signs of shock include cold and sweaty skin, rapid breathing, a blue skin tone, or a weak and rapid pulse. Call 9-1-1 if you notice signs of shock in yourself or someone else.

Talk to your doctor about your symptoms. Your doctor will use a blood pressure test to diagnose low blood pressure. Other tests may include blood, urine, or imaging tests and a tilt table test if you faint often.

How is it treated?

You may not need treatment for low blood pressure. Depending on your symptoms, treatment may include drinking more fluids to prevent dehydration, taking medicines to raise your blood pressure, or adjusting medicines that cause low blood pressure.

Your doctor may talk to you about lifestyle changes, including changing what and how you eat and how you sit and stand up. Your doctor may also recommend compression stockings if you stand for long periods.

Learn more about Low Blood Pressure from the U.S. National Library of Medicine.