Overview
Low blood pressure is generally considered a blood pressure reading lower than 90 millimeters of mercury (mm Hg) for the top number (systolic) or 60 mm Hg for the bottom number (diastolic).
What's considered low blood pressure for one person might be OK for someone else. Low blood pressure might cause no noticeable symptoms, or it might cause dizziness and fainting. Sometimes, low blood pressure can be life-threatening.
The causes of low blood pressure range from dehydration to serious medical conditions. It's important to find out what's causing low blood pressure so that it can be treated, if necessary.
Types
Types of low blood pressure include:
- Orthostatic hypotension (postural hypotension). This is a sudden drop in blood pressure when standing from a sitting position or after lying down. Causes include dehydration, long-term bed rest, pregnancy, certain medical conditions and some medications. This type of low blood pressure is common in older adults.
- Postprandial hypotension. This drop in blood pressure occurs 1 to 2 hours after eating. It's most likely to affect older adults, especially those with high blood pressure or autonomic nervous system diseases such as Parkinson's disease. Eating small, low-carbohydrate meals, drinking more water, and avoiding alcohol might help reduce symptoms.
- Neurally mediated hypotension. This is a blood pressure drop that happens after standing for long periods. This type of low blood pressure mostly affects young adults and children. It might result from miscommunication between the heart and the brain.
- Multiple system atrophy with orthostatic hypotension. Also called Shy-Drager syndrome, this rare disorder affects the nervous system that controls involuntary functions such as blood pressure, heart rate, breathing and digestion. It's associated with having very high blood pressure while lying down.
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Symptoms
Low blood pressure (hypotension) symptoms may include:
- Blurred or fading vision
- Dizziness or lightheadedness
- Fainting
- Fatigue
- Trouble concentrating
- Nausea
For some people, low blood pressure may be a sign of an underlying health condition, especially when it drops suddenly or occurs with symptoms.
A sudden fall in blood pressure can be dangerous. A change of just 20 mm Hg — a drop from 110 mm Hg systolic to 90 mm Hg systolic, for example — can cause dizziness and fainting. And big drops, such as those caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening.
Extreme low blood pressure can lead to a condition known as shock. Symptoms of shock include:
- Confusion, especially in older people
- Cold, clammy skin
- Decrease in skin coloration (pallor)
- Rapid, shallow breathing
- Weak and rapid pulse
When to see a doctor
If you have symptoms of extreme low blood pressure (hypotension) or shock, seek emergency medical help.
Most health care providers consider blood pressure to be too low only if it causes symptoms. Occasional minor dizziness or lightheadedness can be caused by many things, such as spending too much time in the sun or in a hot tub. It's important to see a health care provider to get a correct diagnosis.
If you have consistently low blood pressure readings but feel fine, your provider may just monitor you during routine health checkups. It can be helpful to keep a record of your symptoms, when they occur and what you're doing at the time.
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Causes
Blood pressure is determined by the amount of blood the heart pumps and the amount of resistance to blood flow in the arteries. A blood pressure measurement is given in millimeters of mercury (mm Hg). It has two numbers:
- Systolic pressure. The first (upper) number is the pressure in the arteries when the heart beats.
- Diastolic pressure. The second (bottom) number is the pressure in the arteries when the heart rests between beats.
The American Heart Association categorizes ideal blood pressure as normal. An ideal blood pressure is usually lower than 120/80 mm Hg.
Blood pressure varies throughout the day, depending on:
- Body position
- Breathing
- Food and drink
- Medications
- Physical condition
- Stress
- Time of day
Blood pressure is usually lowest at night and rises sharply on waking. Certain health conditions and use of medications may cause low blood pressure.
Conditions that can cause low blood pressure
Medical conditions that can cause low blood pressure include:
- Pregnancy. Changes during pregnancy cause blood vessels to expand rapidly. The changes may cause blood pressure to drop. Low blood pressure is common in the first 24 weeks of pregnancy. Blood pressure usually returns to pre-pregnancy levels after giving birth.
- Heart and heart valve conditions. A heart attack, heart failure, heart valve disease and an extremely low heart rate (bradycardia) can cause low blood pressure.
- Hormone-related diseases (endocrine disorders). Conditions affecting the parathyroid or adrenal glands, such as Addison's disease, may cause blood pressure to drop. Low blood sugar (hypoglycemia) and, sometimes, diabetes also may lower blood pressure.
- Dehydration. When the body doesn't have enough water, the amount of blood in the body (blood volume) decreases. This can cause blood pressure to drop. Fever, vomiting, severe diarrhea, overuse of diuretics and strenuous exercise can lead to dehydration.
- Blood loss. Losing a lot of blood, such as from an injury or internal bleeding, also reduces blood volume, leading to a severe 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). Symptoms of a severe allergic reaction include a sudden and dramatic drop in blood pressure.
- Lack of nutrients in the diet. Low levels of vitamin B-12, folate and iron can keep the body from producing enough red blood cells (anemia), which can lead to low blood pressure.
Medications that can cause low blood pressure
Some medications can cause low blood pressure, including:
- Water pills (diuretics), such as furosemide (Lasix) and hydrochlorothiazide (Microzide)
- Alpha blockers, such as prazosin (Minipress)
- Beta blockers, such as atenolol (Tenormin) and propranolol (Inderal, Innopran XL, Hemangeol)
- Drugs for Parkinson's disease, such as pramipexole (Mirapex) or those containing levodopa
- Certain types of antidepressants (tricyclic antidepressants), including doxepin (Silenor) and imipramine (Tofranil)
- Drugs for erectile dysfunction, including sildenafil (Revatio, Viagra) or tadalafil (Adcirca, Alyq, Cialis), particularly when taken with the heart medication nitroglycerin (Nitrostat, Nitro-Dur, Nitromist)
Risk factors
Anyone can have low blood pressure (hypotension). Risk factors for hypotension include:
- Age. Drops in blood pressure on standing or after eating occur primarily in adults older than 65. Neurally mediated hypotension primarily affects children and younger adults.
- Medications. Certain medications, including some blood pressure drugs, increase the risk of low blood pressure.
- Certain diseases. Parkinson's disease, diabetes and some heart conditions may increase risk of low blood pressure.
Complications
Potential complications of low blood pressure (hypotension) include:
- Dizziness
- Weakness
- Fainting
- Injury from falls
Severely low blood pressure can reduce the body's oxygen levels, which can lead to heart and brain damage.
By Mayo Clinic Staff
FAQs
What can very low blood pressure cause? ›
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.
What are the symptoms of hypotension? ›- Dizziness or lightheadedness.
- Nausea.
- Fainting (syncope)
- Dehydration and unusual thirst.
- Dehydration can sometimes cause blood pressure to drop. However, dehydration does not always cause low blood pressure. ...
- Lack of concentration.
- Blurred vision.
- Cold, clammy, pale skin.
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.
Can low blood pressure cause a stroke? ›Heart problems or stroke: Low blood pressure can cause your heart to try to compensate by pumping faster or harder. Over time, that can cause permanent heart damage and even heart failure. It can also cause problems like deep vein thrombosis and stroke because blood isn't flowing like it should, causing clots to form.
What is the best medicine for low blood pressure? ›- Fludrocortisone. Fludrocortisone is a medication that seems to help some types of low blood pressure. ...
- Midodrine. Midodrine activates receptors on the smallest arteries and veins to produce an increase in blood pressure.
Typically, yes, an episode of hypotension ends quickly; once you sit or lie down, symptoms disappear. The biggest risk for most people who have orthostatic hypotension is injury from a fall. But if you have chronic or recurrent orthostatic hypotension, it may indicate a more serious underlying condition.
Is 80 40 blood pressure too low? ›Low blood pressure is also known as hypotension. People with a reading of around 90/60, or less, are commonly regarded as having low blood pressure. Some people who have low blood pressure experience symptoms as a result of it. There may be an underlying cause that could need treatment.
Is 58 blood pressure normal? ›A normal blood pressure for an adult is defined as 90 to 119 systolic over 60 to 79 diastolic. The range between 120 to 139 systolic and 80 to 89 diastolic is called pre-hypertension, and readings above that indicate hypertension, or high blood pressure.
What should you do if your blood pressure is low and dizzy? ›If you feel dizzy or light-headed, sit down or lie down for a few minutes. Or you can sit down and put your head between your knees. This will help your blood pressure go back to normal and help your symptoms go away. Follow your doctor's suggestions for ways to prevent symptoms like dizziness.
What causes an elderly person's blood pressure to drop? ›Orthostatic hypotension (postural hypotension).
Causes include dehydration, long-term bed rest, pregnancy, certain medical conditions and some medications. This type of low blood pressure is common in older adults.
Does low blood pressure make you tired? ›
Having a lower blood pressure is good in most cases (less than 120/80). But low blood pressure can sometimes make you feel tired or dizzy. In those cases, hypotension can be a sign of an underlying condition that should be treated. Hypotension in adults is defined as a blood pressure reading of lower than 90/60 .
What home remedy is good for low blood pressure? ›- Eat more salt. ...
- Avoid alcoholic beverages. ...
- Discuss medications with a doctor. ...
- Cross legs while sitting. ...
- Drink water. ...
- Eat small meals frequently. ...
- Wear compression stockings. ...
- Avoid sudden position changes.
Fludrocortisone is recommended as first-line drug therapy. This is a drug that prevents dehydration by causing the kidneys to retain water. This drug boosts the blood volume, which raises the blood pressure.
When should you go to ER for low blood pressure? ›In rare cases, low blood pressure can become a medical emergency. If you are experiencing mental confusion, blue or pale skin, loss of consciousness, difficulty breathing, low pulse, or other severe symptoms, call 9-1-1 or go to your nearest emergency room for immediate medical attention.
Can you live with hypotension? ›Also called hypotension, low blood pressure is not a problem if you're healthy and show no signs or symptoms of the condition. However, abnormally low blood pressure can cause problems such as dizziness and fainting and can be a sign that other serious conditions, such as heart disease, are present.
Is 60 over 40 a good blood pressure? ›Your ideal blood pressure is between 90/60 mmHg and120/80 mmHg. If it gets too low, then you have low blood pressure, or hypotension.
What is normal blood pressure for a 70 year old? ›New Blood Pressure Standards for Seniors
The ideal blood pressure for seniors is now considered 120/80 (systolic/diastolic), which is the same for younger adults. The high blood pressure range for seniors starts at hypertension stage 1, spanning between 130-139/80-89.
Severe hypotension caused by shock is a medical emergency. You may be given: Blood through a needle (IV) Medicines to increase blood pressure and improve heart strength.
How do paramedics treat low blood pressure? ›Treatment Strategies
In some patients, hypotension is due to dehydration, and so the first line of defense usually involves giving fluids. This may also help if the patient is suffering from an endocrine disorder, medication reaction, blood loss, or anemia.
Caffeine. Coffee and caffeinated tea may temporarily spike blood pressure by stimulating the cardiovascular system and boosting your heart rate.
Is 90 over 55 too low for blood pressure? ›
If your blood pressure is 120/80 millimeters of mercury (mm Hg) or lower, it's considered normal. Generally, if the blood pressure reading is under 90/60 mm Hg, it is abnormally low and is referred to as hypotension.
Which number is more important in blood pressure? ›While both numbers in a blood pressure reading are essential for diagnosing and treating high blood pressure, doctors primarily focus on the top number, also known as systolic pressure.
Can low blood pressure make you ill? ›If your blood pressure is naturally low, it's unlikely to cause any symptoms or require treatment. However, low blood pressure can sometimes mean there's not enough blood flowing to your brain and other vital organs. This can lead to symptoms such as: dizziness or lightheadedness.
How can I raise my blood pressure immediately in an emergency? ›Treating the cause of the shock often helps to raise blood pressure. For example, in anaphylactic shock, an injection of epinephrine (EpiPen) helps to quickly raise blood pressure.
Is it OK to live with low blood pressure? ›Also called hypotension, low blood pressure is not a problem if you're healthy and show no signs or symptoms of the condition. However, abnormally low blood pressure can cause problems such as dizziness and fainting and can be a sign that other serious conditions, such as heart disease, are present.
What medications cause low blood pressure? ›- Alcohol.
- Anti-anxiety medicines.
- Certain antidepressants.
- Diuretics.
- Heart medicines, including those used to treat high blood pressure and coronary heart disease.
- Medicines used for surgery.
- Painkillers.
In rare cases, low blood pressure can become a medical emergency. If you are experiencing mental confusion, blue or pale skin, loss of consciousness, difficulty breathing, low pulse, or other severe symptoms, call 9-1-1 or go to your nearest emergency room for immediate medical attention.
How do hospitals treat low blood pressure? ›- Compression stockings or abdominal binder: These may help promote blood return to your heart and decrease your hypotension.
- IV fluids: These may be used to increase your BP if you are dehydrated, have blood loss, or sepsis.
- A blood transfusion replaces blood in your body to help it work properly.