What Is Ischemia? Overview, Causes, and More

Doctors use the term ischemia to describe a reduction in blood flow to a certain part of the body. It can affect any body part, including the heart, brain, muscle, and intestines. Ischemia can be acute, due to a sudden reduction in blood flow, or chronic, due to slowly decreasing blood flow. It requires medical attention because it can cause potentially life threatening complications.

This article explains what ischemia is. It also outlines common symptoms and causes of certain types of the condition.

Ischemia is any reduction in blood flow resulting in decreased oxygen and nutrient supplies to a tissue.

Ischemia may be reversible, in which case the affected tissue will recover with the restoration of blood flow, or irreversible, which can result in tissue death.

Ischemia can occur anywhere in the body. Heart attacks and strokes both result from ischemia.

The condition takes a different name depending on where in the body it occurs. For example:

• Cardiac or myocardial ischemia means that there is a lack of blood flow and oxygen in the heart.
• Mesenteric ischemia means that the ischemia is affecting the intestines.
• Critical limb ischemia can be a complication of peripheral artery disease. It means that blood flow to the legs is restricted.

Because ischemia can lead to permanent injury, acute ischemia is always a medical emergency. 

Seek immediate medical care by calling 911 if you experience: 

• chest pain or pressure
• difficulty breathing
• a severe headache
• abdominal pain
• sudden difficulties with memory, thinking, talking, comprehension, writing, or reading
• confusion or a loss of consciousness, for even a brief moment
• numbness
• paralysis or an inability to move a body part
• a loss of vision or changes in vision
• impaired balance and coordination
• vomiting blood
• rectal bleeding or bloody stool
• profuse sweating
• unusual anxiety
• a cold, blue, or darkened extremity or patch of skin

Seek prompt medical care if you are receiving treatment for ischemia but mild symptoms persist or if you start to develop:

• mild shortness of breath
• a limitation of physical abilities
• gradual memory loss
• gradual skin changes
• sores on the leg or foot that do not heal
• leg pain when walking or climbing stairs
• abdominal discomfort while eating
• other symptoms that cause you concern

Although pain is a common symptom, ischemia may occur without any symptoms. Generally, symptoms depend on the location of the ischemia.

Sometimes, cardiac ischemia does not cause any symptoms. This is called silent ischemia.

However, some people with cardiac ischemia may notice chest pain, or angina. This may feel like a tightness or squeezing pain.

Learn how to talk with a doctor about angina here.

People may also experience changes in their heart rhythm due to cardiac ischemia. This can include a fast heart rate, called ventricular tachycardia, or ventricular fibrillation, which is another type of arrhythmia.

People with these heart rhythm changes may also experience fainting.

Learn when to go to the emergency room for a fast heart rate here.

Sometimes, people refer to coronary heart disease (CHD) as ischemic heart disease. However, it is important to note that it is possible to experience ischemia without obstructive CHD.

Symptoms of ischemia of the brain include:

• changes in heart rate
• changes in blood pressure
• faintness or fainting
• sensory loss
• difficulty talking
• difficulty performing basic calculations
• difficulty with coordination or balance
• unresponsiveness to stimuli, including people and objects
• visual disturbances, including double vision

Ischemia of the brain can also cause a stroke. Receiving prompt treatment can improve the outlook for a stroke, so it is important to be aware of the early symptoms of this condition.

Learn about the warning signs of a stroke here.

Symptoms of mesenteric ischemia, which affects the intestines, include:

• abdominal pain
• diarrhea
• blood in the stool
• nausea or vomiting
• dehydration
• unexplained weight loss
• heart rhythm changes

In some cases, ischemia can be life threatening. Seek immediate medical care by calling 911 if you or someone you are with have any of the following life threatening symptoms:

• abnormal pupil size or nonreactivity to light
• changes in consciousness or alertness, such as passing out or being unresponsive
• chest pain, chest tightness, chest pressure, and palpitations
• droopy eyelids
• garbled or slurred speech or an inability to speak
• hallucinations
• paralysis or an inability to move a body part
• respiratory or breathing problems, such as shortness of breath
• seizures
• severe abdominal pain or headaches
• a sudden change in vision or a loss of vision
• vomiting blood or bloody stool

Ischemia can have different causes depending on which part of the body it affects. For example:

• Cardiac ischemia: Cardiac ischemia usually happens when the arteries have become narrowed due to a buildup of plaque. If the heart has to work harder than usual, such as due to high blood pressure, it can cause ischemia to the heart muscle. People with a history of heart attacks have a higher chance of developing cardiac ischemia.
• Brain ischemia: Brain ischemia can happen because of shock, low blood pressure, or conditions that affect the autonomic nervous system, such as vasovagal syncope or postural tachycardia syndromes. Problems with the structure and function of the heart, including arrhythmias, can also cause brain ischemia. Thrombosis or embolism can also cause blockages that lead to focal brain ischemia.
• Intestinal ischemia: About half of all cases of acute mesenteric ischemia happen because of an embolism. This can come from blockages in the heart due to arrhythmias such as atrial fibrillation (AFib) or from conditions such as atherosclerosis. Sometimes, intestinal ischemia can happen because of other blockages in organs such as the spleen or kidney. Hernias, scar tissue, and low blood pressure can also contribute to intestinal ischemia.

A number of factors increase the risk of developing ischemia. However, it is worth noting that not all people with risk factors for ischemia will experience the condition.

Some risk factors for ischemia include:

• AFib
• heart disease
• diabetes
• high blood pressure
• high cholesterol or triglycerides
• obesity or overweight
• physical inactivity
• stress
• tobacco or alcohol use
• trauma
• underlying vascular disease
• venous thromboembolism

The treatment of ischemia begins with seeking regular medical care throughout your life. Receiving regular medical care allows a healthcare professional to provide early screening tests and promptly evaluate your symptoms and your risk of developing ischemia.

The goal of treating ischemia is to restore blood flow and prevent further damage. Surgery may be necessary to remove dead tissue or repair injured areas.

Once the initial event is under proper control, treatment will turn to the prevention of future ischemia.

Treatments for ischemia will depend on which part of the body it is affecting.

Some common treatments to reduce ischemia and restore blood flow include:

• medications to control pain and dilate blood vessels
• medications to prevent ongoing clot formation
• medications to reduce the heart’s workload
• antibiotics
• oxygen therapy
• procedures to expand blood vessels
• surgery or procedures to remove clots
• surgery to bypass blocked blood vessels
• thrombolytic drugs to dissolve clots

Learn how to find the right doctor for heart bypass surgery here.

Complications of untreated ischemia can be serious or even life threatening. You can help minimize your risk of experiencing serious complications by following the treatment plan that you and your healthcare professional design specifically for you.

The complications of ischemia will depend on where the condition is affecting the body, but they can include:

• altered or decreased sensation
• amputation
• blindness
• bowel perforation or loss
• decreased cognitive function
• heart failure
• paralysis or weakness
• permanent disability

You may be able to lower your risk of ischemia by:

• controlling your blood sugar
• eating a healthy diet
• engaging in regular physical activity
• maintaining a moderate weight
• quitting smoking and other tobacco products
• reducing your stress level
• taking medications as recommended for heart disease, cholesterol, diabetes, or high blood pressure

Maintaining regular contact with a doctor can help lower your risk of ischemia and its complications.

Ischemia means that there is a reduced blood and oxygen supply to a certain part of the body. Locations in the body this condition can affect include the heart, intestines, brain, and limbs.

Ischemia can happen due to structural or functional problems in the heart, but it can have a variety of causes. It also has many triggers, including stress and trauma.

The treatment of ischemia will depend on where in the body it is affecting. It may involve surgery to widen the arteries or medications to thin the blood.