Signs of Low Blood Pressure
What are signs of low blood pressure?
Signs of low blood pressure are the observable manifestations of low blood pressure, also known by its medical name of hypotension.
Low blood pressure occurs when the force of blood pressing against the artery walls is lower than is usual. Blood pressure can vary throughout the day as a result of factors, such as temperature or simply standing up too quickly. Some people also have naturally low blood pressure.
In general, low blood pressure is only of medical concern if it is lower than what is normal for the individual, as this can restrict the amount of blood and oxygen flow to the body’s organs. Often, this will be linked to an underlying medical condition, such as heart disease.
Signs of low blood pressure can include dizziness and fainting. Treatment will typically involve management of the underlying cause and may involve simple lifestyle changes.
Signs of low blood pressure
There are several types of low blood pressure. Each is linked to a different cause and leads to different signs and symptoms. The four main types of low blood pressure are:
- Chronic asymptomatic hypotension
- Orthostatic hypotension
- Neurally mediated hypotension
- Severe hypotension linked to shock
Signs of chronic asymptomatic hypotension
People who have low blood pressure all the time have chronic asymptomatic hypotension. This type of low blood pressure is normal for them and will typically cause no signs or symptoms.
Signs of orthostatic hypotension
Orthostatic hypotension, or postural hypotension, occurs when a person stands up from a sitting or lying position too quickly. This type of low blood pressure results from the body being unable to adjust its blood pressure fast enough after a change in position.
Signs and symptoms of orthostatic hypotension include:
- Blurred vision
Although it can occur in anyone, it is most common in older people. Orthostatic hypotension may also be a sign of an underlying medical condition, such as a cardiovascular disorder, anemia or dehydration. Certain types of medication, including diuretics, calcium channel blockers and nitrates, can also increase the risk of experiencing this types of low blood pressure.
Postprandial hypotension is a variant of orthostatic hypotension. This type of low blood pressure occurs following a meal. Again, older people are most at risk of postprandial hypotension, and it may be linked to conditions such as high blood pressure and Parkinson’s disease.
Signs of neurally mediated hypotension
Neurally mediated hypotension (NMH) occurs after a person has been standing for an extended period of time. In rarer cases, NMH may occur during or following a frightening or unpleasant situation. This type of low blood pressure is caused by the brain and heart not communicating with each other properly.
Typical signs and symptoms of NMH include:
NMH is most common in children and young adults.
Signs of severe hypotension linked to shock
Shock is a serious condition that occurs when blood pressure falls so low that the body’s organs receive too little blood to function properly.
Shock can be caused by a variety of factors, including internal and external bleeding, severe infection, severe kidney disease and severe diarrhea.
Signs and symptoms of shock include:
- Anxiety and confusion
- Blue lips and/or fingernails
- Chest pain
- Dizziness and lightheadedness
- Pale and/or clammy skin
- Rapid, but weak pulse
- Shallow breathing
- Heart palpitations
Not all people experiencing shock will have all of these symptoms. Shock may also lead to a loss of consciousness prefaced by neurological symptoms, such as confusion. Shock is a life-threatening condition that requires urgent medical attention.
Signs of low blood pressure in pregnancy
Low blood pressure is not uncommon during pregnancy. The signs and symptoms of low blood pressure during pregnancy are similar to those experienced by people who are not pregnant and include:
Pregnant women who experience these symptoms should contact a doctor for evaluation.
Pregnant women should also seek emergency care if they experience dizziness or fainting along with other, more serious symptoms, such as:
- Severe headaches
- Vision changes
- Chest pain
- Shortness of breath
Good to know: Severe headaches, vision disturbances and pain can also be a sign of preeclampsia.
Low blood pressure diagnosis
A diagnosis of low blood pressure will generally be given after a doctor has asked about the individuals symptoms, performed an examination and administered a blood pressure test.
Blood pressure test readings are given as two numbers, for example 150 over 80 mmHg (150/80). The first figure – the systolic level – shows the pressure inside the arteries as blood is pumped out of the heart. The second figure – the diastolic level – shows the lowest pressure inside the arteries between heartbeats. A reading of 90 over 60 mmHg (90/60) or less is generally regarded as indicating low blood pressure.
A doctor may also perform a tilt test during diagnosis. During this test, the individual is positioned on a special table and slowly tilted upwards to allow the doctor to see how the motion affects blood pressure.
Low blood pressure treatment and prevention
People with naturally low blood pressure and who experience no symptoms will require no treatment. However, people who have abnormally low blood pressure and who are experiencing symptoms, will be advised by doctors to take a variety of simple steps to help manage the condition and prevent the onset of symptoms. In cases where these measures do not help, or when blood pressure is significantly low, medication may also be prescribed.
- Standing up or sitting down slowly
- Crossing the legs, standing on the tip-toes or tensing the muscles while standing to promote blood flow
- Avoiding triggers such as high temperatures or frightening situations
- Raising the head slightly while sleeping
- Wearing support stocking to help promote blood flow
- Drinking plenty of fluids
- Eating smaller meals
In some cases, medication may be prescribed to help treat low blood pressure. The choice of medication will depend on the particular case but may include midodrine, fludrocortisone and droxidopa.
American Family Physician. “Evaluation and Management of Orthostatic Hypotension.” September, 2011. Accessed June 7, 2018. ↩