Low Blood Pressure Hypotension

Low blood pressure (Hypotension) may seem like something people desire, but it isn’t so much of a good thing.

While for some people, low blood pressure doesn’t pose any threats, for others, it could be dangerous as is caused dizziness and sometimes fainting. Low blood pressure can be threatening in severe cases.

Any measured blood pressure that reads lower than 60 mm Hg for the bottom number (diastolic) or 90 millimeters of mercury (mm Hg) for the top number (systolic) is generally considered low.

There are several causes of low blood pressure, and they can range from dehydration to life-threatening medical or surgical disorders. It is vital to find out what the cause of your low blood pressure is so that it can easily be treated.


For some individuals, low blood pressure is a sign of an underlying problem, especially the blood pressure suddenly drops or is accompanied by signs and symptoms like:

  • Fainting (syncope)
  • Dizziness or lightheadedness
  • Blurred vision
  • Fatigue
  • Nausea
  • Lack of concentration


Shock is a life-threatening condition that may be caused by Extreme hypotension. The likely signs and symptoms of shock due to hypotension include:

  • Cold, clammy, pale skin
  • Confusion, especially in older people
  • Weak and rapid pulse
  • Rapid, shallow breathing
  • When Should you see a doctor?

If you have noticed any indications of shock, request for emergency medical help.

However, if you consistently have low blood pressure readings, but you feel fine, all your doctor will likely do is to monitor you every time you go for routine exams.

Even cases of occasional dizziness or lightheadedness will be considered a relatively minor problem — the outcome of mild dehydration resulting from spending too much time in the sun or in a hot tub, for instance.

Still, you must see a doctor if you notice any signs or symptoms of hypotension as they may point to more serious medical problems. A useful tip that you may want to consider is keeping a record of your symptoms when they occur, as It can be helpful.

That way, you know exactly what you were doing at the time it happened.

Basic measurement information

Your blood pressure is basically the measurement of the pressure in your arteries during every active and resting phases of your heartbeat.

Systolic pressure

This is the top number in a blood pressure reading. This part measures the amount of pressure your heart generates when it pumps blood through your arteries to other parts of your body.

Diastolic pressure

This is the bottom number in a blood pressure reading. This part measures the amount of pressure in your arteries each time your heart is at rest between beats.

According to current guidelines, healthy blood pressure should be lower than 120/80 mm Hg.

Blood pressure varies throughout the day, depending on breathing rhythm, body position, stress level, physical condition, what you eat and drink, medications you take, and time of day. Usually, blood pressure is meant to be at its lowest at night and rise sharply on waking in the morning.

Blood pressure: How low can you go?

What your doctors considered low blood pressure for you might be what is deemed to be healthy for someone else. Most doctors will only find blood pressure too low if it causes symptoms for people.

Some experts have defined low blood pressure as any reading that is lower than 90 mm Hg systolic or 60 mm Hg diastolic. If either the diastolic or systolic number is below that, then a person’s blood pressure is lower than average.

A sudden fall in blood pressure can be dangerous. A seemingly small change of just 20 mm Hg — or a drop from 110 systolic to 90 mm Hg systolic, for instance — can lead to dizziness and fainting when a person’s brain fails to receive an adequate supply of blood.

Any big plunges, like those that are caused by uncontrolled bleeding, allergic reactions, or severe infections, can be life-threatening.

Conditions that can cause low blood pressure

Many medical conditions can cause low blood pressure, and they include:


Because during pregnancy, the circulatory system rapidly expands, blood pressure is most likely to drop. This is a very regular occurrence, and blood pressure will often return to your pre-pregnancy level once you have given birth.

Heart problems

Certain heart conditions are known to lead to low blood pressure, and they include extremely low heart rate (bradycardia), heart attack, heart valve problems, and heart failure.

Endocrine problems: Thyroid conditions like adrenal insufficiency (Addison’s disease), parathyroid disease, low blood sugar (hypoglycemia) and, and, sometimes, diabetes may trigger low blood pressure.


This is a common cause of low blood pressure. When your body loses more liquid than it takes in, it can lead to weakness, fatigue, and dizziness. Vomiting, fever, severe diarrhea, overuse of diuretics, and even strenuous exercise may lead to dehydration.

Blood loss

Losing so much blood, such as from internal bleeding or a significant injury, causes a drop in the amount of blood in your body, and that leads to a severe decline in blood pressure.

Severe infection(septicemia)

Whenever an infection in the body finds it’s way into the bloodstream, it can cause a life-threatening drop in blood pressure levels, and this is known as septic shock.

Severe allergic reaction (anaphylaxis)

Some of the common triggers of this potentially life-threatening reaction may include foods, insect venoms, certain medications, and latex. Anaphylaxis can lead to hives, breathing problems, itching, a swollen throat as well as a dangerous drop in blood pressure.

Lack of nutrients in your diet

It is also possible for lack of vitamins B-12 and folate in the foods you eat to keep your body from producing adequate amounts of red blood cells (anemia), and that ultimately leads to low blood pressure.

Medications that can cause low blood pressure

Some medicines have been noticed to cause low blood pressure, and they include:

  • Water pills (diuretics), such as hydrochlorothiazide (Maxzide, furosemide (Lasix), and Microzide, others)
  • Alpha-blockers, such as prazosin (Minipress)
  • Drugs for Parkinson’s disease, such as pramipexole (Mirapex) or other ones containing levodopa
  • Beta-blockers, such as atenolol (Tenormin) and propranolol (Inderal, Innopran XL, others)
  • Certain types of antidepressants (tricyclic antidepressants), including imipramine (Tofranil), or doxepin (Silenor)
  • Drugs for erectile dysfunction, tadalafil (Adcirca, Cialis) or including sildenafil (Revatio, Viagra), particularly when taken with the heart medication known as nitroglycerin

Types of low blood pressure

Doctors usually break down low blood pressure (hypotension) into diffident categories, depending on the cause and other factors. The examples of low blood pressure include but are not restricted to the following:

Low blood pressure on standing up (orthostatic, or postural, hypotension)

This type of hypotension is a sudden drop in blood pressure when a person stands up from a sitting position or after you lie down. Gravity naturally causes blood to pool in your legs when you get up from a lying or sitting position.

Ordinarily, your body will have to compensate by increasing your heart rate and also constricting blood vessels, ultimately making sure that enough blood goes back to your brain.

But in people who have orthostatic hypotension, there is a failure in this compensating mechanism, and it causes blood pressure to fall, leading to lightheadedness, dizziness, blurred vision, and sometimes fainting.

Orthostatic hypotension can happen for various reasons, including prolonged bed rest, dehydration, pregnancy, diabetes, burns, heart problems, excessive heat, certain neurological disorders, and large varicose veins.

Several medications can also cause orthostatic hypotension, especially medicines that are used to treat high blood pressure — beta-blockers, diuretics, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors.

Other culprits are antidepressants and medications that are used to treat Parkinson’s disease and erectile dysfunction.

Orthostatic hypotension is most common in older adults; however, it is also possible to notice it in young people, otherwise healthy people who stand up suddenly after sitting with their legs crossed for long periods or after squatting for a time.

It’s also possible for a person to have delayed orthostatic hypotension, with signs and symptoms showing up only 5 to 10 minutes after a person has a change in posture. Sometimes, this might be a milder form of hypotension, or it may be an early stage of it.

Low blood pressure after eating (postprandial hypotension)

This type is a sudden drop in blood pressure after a meal. This one mostly affects older adults. Blood will flow to your digestive tract after a meal.

Typically, your body will increase your heart rate and then constrict certain blood vessels in an attempt to maintain healthy blood pressure. However, this mechanism fails in some people, leading to fainting, dizziness, and falls.

Postprandial hypotension is more likely to affect people with high blood pressure or autonomic nervous system disorders like Parkinson’s disease.

Lowering the dose of blood pressure medications and eating small, low-carbohydrate meals may help to reduce symptoms of this type of hypotension. Low blood pressure from faulty brain signals (neurally mediated hypotension).

This is a disorder, which causes blood pressure to drop after a person stands for long periods. It mostly affects children and young adults.

It usually occurs because of a miscommunication between the brain and heart — low blood pressure due to nervous system damage (multiple system atrophy with orthostatic hypotension).

A multiple system atrophy with orthostatic hypotension is also called Shy-Drager syndrome. It is a rare disorder that causes progressive damage to a person’s autonomic nervous system, which is responsible for controlling involuntary functions such as heart rate, blood pressure, breathing, and digestion.

It is associated with having very high blood pressure while lying down.

Risk factors of hypotension

Anyone can have low blood pressure (hypotension), though some types of low blood pressure are more common than others depending on a person’s age or other factors:


A drop in blood pressure when you stand or after eating happens primarily in adults older than the age of 65. For children and young adults, they are mostly affected by Neurally mediated hypotension.


Another set of people at risk of suffering hypotension, including those who take certain medications. For instance, high blood pressure medications like alpha-blockers, have a higher risk of low blood pressure.

Specific diseases

Diabetes, Parkinson’s disease, and some heart conditions will put you at an increased risk of developing low hypotension.


The complications from even moderate forms of low blood pressure may lead to weakness, dizziness, fainting, and a higher risk of injury from falls.

And very low blood pressure may deprive your body of the right amount of oxygen to carry out most of its normal functions, and that may lead to damage to your brain and heart.

We hope that the information in this article has been of help to you. Please do not hesitate to leave a comment in the comments section provided below.