There are many kinds of medical shock.

Hypovolemic shock occurs when the body begins to shut down due to the loss of large amounts of blood or fluid. When hypovolemic shock is caused by blood loss, it’s known as hemorrhagic shock.

People with injuries that involve heavy bleeding may go into hemorrhagic shock if the bleeding isn’t stopped immediately.

According to a 2019 study, hemorrhagic shock as a result of injury is the leading cause of death in people ages 1 to 46 years old in the United States.

Common causes of hemorrhagic shock include:

Blood carries oxygen and other essential substances to your organs and tissues. When heavy bleeding occurs, these substances are lost more quickly than they can be replaced. There’s not enough blood flow to the organs in your body, and they begin to shut down.

As your heart shuts down and fails to circulate an adequate amount of blood through your body, symptoms of shock occur. Blood pressure plummets and there’s a massive drop in body temperature, which can be life threatening.

Signs and symptoms of shock are life threatening and should be treated as a medical emergency.

They include:

Usually, in cases of shock, many of these signs and symptoms are present at the same time.

Signs and symptoms of hemorrhagic shock may not appear immediately. External hemorrhaging (bleeding) will be visible. Internal hemorrhaging, however, may be hard to recognize until symptoms of shock appear.

Signs and symptoms of internal hemorrhaging include:

Seek medical attention immediately if you have symptoms of hemorrhaging or hemorrhagic shock. Have someone drive you to the hospital or call 911 or your local emergency services.

DO NOT drive to the hospital on your own if you’re bleeding excessively or if you have any symptoms of shock.

The American College of Surgeon’s Advanced Trauma Life Support program divides hemorrhagic shock into four classes. The classifications are based on the amount of expected blood loss in a healthy person weighing 154 pounds:

  • People with class 1 shock have lost up to 15 percent of their total blood volume.
  • People with class 2 shock have lost 15 to 30 percent of their total blood volume.
  • People with class 3 shock have lost 30 to 40 percent of their total blood volume.
  • People with class 4 shock have lost over 40 percent of their total blood volume.

Call 911 or your local emergency services if someone is bleeding heavily or has symptoms of shock. Also, follow the steps below:

  1. If the person doesn’t have a head injury, neck injury, or spine injury, lay them on their back with their legs elevated 12 inches from the ground. Don’t elevate their head.
  2. Remove any visible dirt or debris from the injury site. DO NOT remove embedded glass, a knife, a stick, an arrow, or any other object stuck in the wound.
  3. If the area is clear of debris and no visible object is protruding from it, tie fabric such as a shirt, towel, or blanket around the injury to minimize blood loss. Apply pressure to the area. If you can, tie or tape the fabric to the injury.
  4. Wait for emergency personnel to arrive.

There are often no advance warnings of shock. Instead, symptoms tend to arise only when you’re already experiencing shock.

A physical examination can reveal signs of shock, such as low blood pressure and a rapid heart rate. Someone in shock may also be less responsive when asked questions by an emergency room doctor.

While heavy bleeding is immediately recognizable, internal bleeding sometimes isn’t found until someone shows signs of hemorrhagic shock. Shock requires immediate attention, so treatment may begin before diagnosis.

If the reason for shock is not obvious, or it’s internal, various tests may be used to diagnose the cause, including:

Your doctor may order a complete blood count (CBC) after addressing the site of the bleeding. The results of this test will let them know whether a blood transfusion is necessary.

Your doctor may also order a blood transfusion without doing a CBC if there’s a large amount of blood loss from the injury. A blood transfusion is given by transferring donor blood into your body intravenously.

The standard treatment for hemorrhagic shock is intravenous (IV) fluid and resuscitation via the administration of blood products.

In some cases, you may be given medications that increase your blood pressure, such as norepinephrine or vasopressin. These are known as vasopressors. People who also have heart dysfunction may be prescribed the vasopressors dobutamine or epinephrine, according to a 2017 study.

Common complications of hemorrhagic shock include kidney damage, other organ damage, and death.

Some people may also develop gangrene due to decreased circulation to the limbs. This infection may result in amputation of the affected limbs.

The outlook will depend on the amount of blood loss and the type of injury. The outlook is best in people with no preexisting health conditions who haven’t had severe blood loss.

Seeking medical help as soon as you notice symptoms of shock will help improve your outlook overall.