When Is Low Blood Pressure An Emergency?

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Many people experience low blood pressure (i.e. “hypotension”). In the majority of cases, they can monitor and manage the issue easily at home. However, if the blood pressure decreases too much or if there is a sudden drop in blood pressure, it becomes an emergency. They should seek advice from a medical professional right away.

That’s why it is important to recognize when hypotension is an emergency. This includes the symptoms and possible underlying causes. In this article, we will explain the leading causes of life-threatening hypotension. 

Three Main Causes Of Low Blood Pressure

Broadly speaking, there are three main causes of low blood pressure. Hypotension develops due to: 

  • Dilation of small arteries
  • Certain heart disorders
  • Decrease in the blood volume

Emergency Symptoms


Based on hospital emergency data, there are more than 1 million cases of shock in the US. 

When blood pressure goes very low, an individual may go into shock. Major organs such as the brain, heart, and kidneys stop working properly because they do not receive enough oxygen. If management of the blood flow does not occur quickly, the organs become irreversibly damaged and begin to die. Multiorgan dysfunction syndrome, (or MODS), is the failure of two or more organs at once. It indicates a significant increase in the risk of death. 

An individual in shock requires emergency treatment in the intensive unit.

  • Hypovolemic shock is when shock develops due to low blood volume.
  • Cardiogenic shock is when the inadequate pumping action of the heart is the cause of the shock
  • Distributive shock is when the cause of shock is excessive dilation of the blood vessels

When blood pressure becomes and emergency 

Here are the key symptoms that suggest the low blood pressure is life-threatening and emergency treatment is necessary:

  • Blood pressure is abnormally low (sometimes to the point where the blood pressure monitor can’t read it)
  • Mental status changes (confusion, lethargy, disorientation )
  • The pulse is weak and rapid (in distributive shock, the pulse can be strong and then become weak)
  • Breathing is rapid and shallow
  • Excessive sweating 
  • Increased thirst and decreased urination
  • Skin changes (either cold, clammy, pale, and bluish, or warm and flushed) 
  • Low blood sugar levels
  • Loss of consciousness

Hypovolemic Shock

In hypovolemic shock, there is low blood volume due to severe bleeding. This can be a result of, for example, major trauma or internal bleeding from a stomach ulcer. A second reason for low blood volume is the severe loss of body fluids. Examples include major burns, pancreatitis, and intestinal perforation of kidney diseases. In rare cases, low blood volume leading to hypovolemic shock is due to not drinking enough fluids. This can happen in advanced cases of  Alzheimer’s disease. 


  • In the early phase, a person may just feel sluggish, sleepy, and confused. 
  • Sitting up may be difficult because it makes that person feel lightheaded (as if they’re about to pass out). 
  • The blood pressure is low. It can become so low that a regular blood pressure monitor can not read it. 
  • The pulse is often weak and rapid.
  • Breathing is rapid and shallow.
  • The skin is cold, sweaty, bluish, and pale. Even the earlobes, nose, and nailbeds may become bluish. If you apply a little pressure on the skin, the color will return much slower than normal.
  • The urine output decreases, and in late stages, it stops. Left untreated, a person in hypovolemic shock may go into a coma and die.

Cardiogenic Shock

In cardiogenic shock, the heart suddenly is unable to pump enough blood to meet the body’s needs. In many cases, cardiogenic shock happens due to a heart attack. Other causes include blood clots in the lungs, abnormal heart rhythms, infections of the heart, problems with the heart valves (i.e. especially artificial valves), or cardiac tamponade (sudden fluid buildup in the sac around the heart).

The symptoms of cardiogenic shock are similar to those of hypovolemic shock (find above).

Distributive Shock

The dilation of blood vessels may be due to threatening allergic reactions (like anaphylactic shock). Dilation could also be due to serious bacterial infections (i.e. septic shock), injuries to the spinal cord, or hormonal disorders like Addison disease. Drug overdoses and poisons can also lead to distributive shock.

The blood pressure is dangerously low, but the symptoms of distributive shock are different from hypovolemic or cardiogenic shock. 

Here are the symptoms to watch for:

  • The skin is rather warm and flushed.
  • The pulse is strong, especially at first.
  • As the condition progresses, this shock can also lead to cold clammy skin and lethargy.
  • In the case of anaphylaxis, a person may experience urticaria and wheezing. 
  • Fever and chills are suggestive of an infection (i.e. septic shock).

Many symptoms may not develop at the beginning, especially in the elderly, who may just have low blood pressure and look a little confused. 

First Aid And Treatment For Shock

If you suspect you are experiencing a shock, call 911 right away. While you are waiting for the ambulance, provide first aid until help arrives. 

  • Lay the person down, if possible
  • Raise the person’s feet about 12 inches off the ground (unless there is an injury to the spine or fracture)
  • Don’t raise the person’s head
  • Turn him/her on the side in case of vomiting or bleeding 
  • Perform CPR, if the person if the breathing is very weak or absent. Continue CPR until help arrives.
  • Keep the person warm and comfortable by loosening the clothes. Cover with a blanket and offer reassurance.
  • Do not give fluids or foods 

For reference, see how to perform CPR on adults, and on children.

At the hospital, emergency physicians will look for the underlying cause of the shock. They will treat the shock with intravenous fluids and supportive care.

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