Hemodynamic instability is an insufficient blood flow in the body. It is a potential symptom of several conditions, such as high blood pressure or heart disease.

Hemodynamics often refers to the basic measures of cardiovascular functions, or how well the blood flows through the body.

Hemodynamic instability describes the unstable movement of blood that results in inadequate blood flow. It is a condition or state in which a person’s cardiovascular functions become unreliable, insufficient, or otherwise problematic due to an underlying condition, such as high blood pressure.

The instability can lead to problems with the cardiovascular system. A person cannot develop hemodynamic instability without an underlying problem in their cardiovascular system. The condition can be a symptom or sign of one or more potential underlying conditions, such as heart disease or hypertension.

Hemodynamic instability can refer to several aspects of blood flow, though many health experts consider a person to have instability when their blood pressure measurements are notably high or low. However, they often do not define the exact severity of the condition.

A doctor may refer to hemodynamic instability as:

In this article, we will discuss hemodynamic instability, its symptoms, causes, risk factors, and more.

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A person may experience symptoms related to hemodynamic instability or the underlying condition responsible for the condition. If a person’s blood flow is unstable, they experience symptoms such as:

Other signs or symptoms may include:

  • slow refilling of capillaries
  • weak or nonexistent pulse in extremities such as arms or legs
  • low blood pressure or unusual blood pressure

A person experiencing any of these symptoms should seek medical care, particularly if they are living with an underlying condition that affects their heart. A healthcare professional can diagnose and provide treatment for the underlying condition.

Several different conditions can cause hemodynamic instability. Generally, any condition that affects the heart or blood flow can cause instability. Potential causes may include:

In some cases, a person may develop instability when under general anesthesia. However, as evidence notes, there is no consensus on exactly what defines instability, with many healthcare professionals using blood pressure as the sole measure.

Certain conditions, treatments, and medications can increase a person’s risk of developing hemodynamic instability.

According to a 2019 study, following a ST‐segment–elevation myocardial infarction, which is a type of heart attack, a person has roughly double the risk of developing issues with blood flow compared with those who have a different type.

Treating certain conditions can also increase a person’s risk of developing hemodynamic instability. For example, treatment for two rare forms of tumor, pheochromocytoma and paraganglioma, can lead to a high risk of developing hemodynamic instability.

Renal replacement therapy may also increase a person’s risk of developing unstable blood flow.

Certain medications may increase a person’s risk of developing hemodynamic instability. Doctors often use vasopressin to help treat septic shock. However, discontinuing vasopressin can lead to hemodynamic instability, specifically, low blood pressure.

To diagnose hemodynamic instability, a healthcare professional will typically start with a physical examination of the person. They will measure their vital signs, such as blood pressure and pulse. They may look for signs such as cool extremities and pulmonary (lung) congestion.

A doctor may also order additional laboratory tests, such as a comprehensive metabolic panel and measurement of a person’s troponin levels.

If a doctor suspects issues with blood flow, they will likely order an electrocardiogram (ECG) within 10 minutes of initial signs. They may also order additional testing to monitor and help determine the cause. This may include:

Treatment may vary depending on the underlying cause of hemodynamic instability.

A doctor will seek to stabilize the person’s blood flow. To do this, they will likely do one or more of the following:

A doctor will provide additional therapy to treat any underlying condition. This can vary greatly depending on the exact cause.

Hemodynamic instability refers to an unstable blood flow in the body. It is associated with several conditions and situations. For example, heart disease and other conditions that affect the heart can lead to hemodynamic instability.

Similarly, treatment for some conditions can cause or increase a person’s risk of developing the condition.

A person with hemodynamic instability is at a high risk of potential complications. The condition can lead to death. To manage symptoms, a doctor will take steps to treat and monitor a person’s blood flow.