Ischemic vs Hemorrhagic Stroke

Your brain needs adequate blood flow and oxygen to do all the activities you might take for granted, like thinking, moving, speaking, and breathing. If blood flow to the brain gets disrupted as it does in a stroke, it can quickly cause disability or even death. In fact, stroke is the fifth most common cause of death in the United States, according to the American Stroke Association (ASA).

“The human brain is a very ‘needy’ organ, and that’s why it requires a high blood volume. When the blood flow is disrupted, brain cells begin to die. This can happen within minutes,” says Natalia S. Rost, MD, MPH, FAAN, FAHA. Dr. Rost is a Mass General Brigham neurologist and chief of the Stroke Division at Massachusetts General Hospital.

There are two main types of strokes. Dr. Rost explains the differences between ischemic and hemorrhagic strokes, and how they’re treated and prevented.

Different types of strokes

There are two main types of stroke:

1. Ischemic stroke, where an artery is blocked (usually by a blood clot).
2. Hemorrhagic stroke, where an artery leaks or ruptures in the brain, causing a bleed (hemorrhage) in the brain tissue.

Ischemic strokes

Ischemic strokes are the most common, making up 87% of all strokes, according to the ASA. Blood clots can form on the inside of blood vessels, especially when the arteries harden or narrow in conditions like arteriosclerosis or atherosclerosis. In atherosclerosis, plaque (made up of cholesterol and other substances) builds up on the artery walls, restricting blood flow and raising blood pressure. In turn, higher blood pressure can cause plaque to break off and form blood clots.

“This process can affect both larger vessels feeding the brain (like carotid arteries) and the smallest ones, deep inside the brain,” Dr. Rost explains.

Other causes of blood clots that can increase the risk of an ischemic stroke include:

• Blood clots forming elsewhere in the body that then travel to the brain. This can happen with atrial fibrillation, a type of cardiac arrhythmia, or deep vein thrombosis, a clotting condition that causes clots in the legs that can then travel to the brain.
• Artery dissection (a tear in the blood vessel)
• Infection, such as COVID-19 or hepatitis C, as cited in the Journal of the American Heart Association
• Use of illicit drugs, or misuse of prescription medication, including cocaine, amphetamines, heroin, and opioids. “This can cause a vessel spasm and lead to the interruption of blood flow,” says Dr. Rost.

If the blood clot gets lodged in an artery and blocks blood flow to the brain, brain cells lose oxygen and die. This can cause paralysis, disability, and even death.

Hemorrhagic strokes

Hemorrhagic strokes happen when a weakened blood vessel leaks or ruptures, bleeding into the surrounding brain. The bleeding disrupts the brain’s normal blood flow and causes pressure buildup, damaging and killing brain cells.

There are two types of hemorrhagic stroke:

1. Subarachnoid hemorrhage: Bleeding between the brain and the membrane that surrounds it
2. Intracerebral hemorrhage: Bleeding inside the brain itself

Like an ischemic stroke, hemorrhagic strokes can cause permanent or fatal brain damage.

Ischemic stroke symptoms vs. hemorrhagic symptoms

Ischemic and hemorrhagic stroke signs and symptoms are often similar and appear suddenly. Warning signs can include:

• Numbness or weakness in the face or limbs, especially on one side of the body
• Difficulty speaking or understanding speech
• Problems with vision in one or both eyes
• Trouble with balance, walking, and dizziness
• Sudden and severe headache
• Confusion
• Loss of consciousness

Signs and symptoms that may be unique to hemorrhagic stroke can include:

• Seizures
• Neck pain or stiffness
• Trouble swallowing or abnormal tastes in the mouth
• Increased sensitivity to light
• Irregular heartbeat or breathing

Treatment for ischemic vs. hemorrhagic strokes

Getting prompt treatment for a stroke is essential. What should you do in a stroke emergency? Remember the acronym FAST, which stands for the following:

• Facial drooping
• Arm weakness
• Speech difficulties
• Time

Dr. Rost notes that a new acronym, BE FAST, has been developed to help with the under-diagnosis of stroke. “BE” includes the following stroke symptoms to look out for, in addition to FAST:

• Balance problems
• Eyes — sudden loss of vision or double vision

The sooner stroke treatment begins, the better the outcome.

“The most important rule of stroke care is to call 911 right away to get the best possible care available for your stroke. As neurologists, we say 'time is brain,' which means that with every passing minute since stroke onset, brain cells get irreversibly damaged. There is no time to be lost in treating stroke,” Dr. Rost says.

Ischemic stroke treatment

For ischemic strokes, health care teams can use a clot-busting medicine called a tissue plasminogen activator (TPA). TPA helps dissolve or break up the blood clot causing the blockage. Another option is a thrombectomy, where doctors use a very thin tube called a catheter to go into the blood vessel and remove the clot directly.

“These treatments are extremely time sensitive. TPA must be used within 4.5 hours of symptom onset. Thrombectomies must be used within 24 hours, but advanced imaging of the brain is required,” says Dr. Rost.

Hemorrhagic stroke treatment

Current treatment options are more limited for hemorrhagic strokes. Health care providers often work to lower blood pressure to prevent further bleeding and to decrease swelling of the brain from the bleeding inside the skull. Some stroke patients may need surgery, especially if the stroke was caused by an aneurysm (a weakened, bulging area of a blood vessel) or malformed blood vessels (like in an arteriovenous malformation or AVM).

“Surgery to repair the blood vessel can be a life-saving option. Care for brain bleeding often requires an advanced level of specialized care (including ICU), thus patients may need to be transported to larger, better equipped medical centers,” says Dr. Rost.

Preventing ischemic and hemorrhagic strokes

“Stroke is just the tip of an iceberg. It’s not the disease itself, it’s a manifestation of an underlying problem in the brain – and the body,” explains Dr. Rost. “Such problems are usually caused by a lifelong exposure to medical conditions we call risk factors.”

Even though ischemic and hemorrhagic strokes have different causes, they have similar risk factors. By making the following lifestyle changes, you can help lower the risk of stroke:

• Control chronic health conditions: High blood pressure (hypertension), high cholesterol, diabetes, and heart diseases like atrial fibrillation all increase the risk of stroke.
• Maintain a healthy weight: Obesity is a risk factor for both heart disease and stroke.
• Quit smoking: Smoking is a risk factor for coronary artery disease and hypertension.
• Limit alcohol use.
• Exercise regularly: Regular exercise can improve and maintain the health of your arteries.
• Eat a healthy diet: Foods that can help prevent stroke include vegetables, whole grains, and lean protein.
• Avoid any unregulated substances or supplements: “This includes marijuana and other drugs,” says Dr. Rost.
• Focus on improving sleep habits and treat disorders like sleep apnea.
• Improve mental health: Activities like talk therapy and meditation can help control stress and anxiety, which are also risk factors for stroke.
• Stay connected: “Studies show that our social networks help improve brain health,” says Dr. Rost.

Dr. Rost also suggests resources from organizations that support stroke patients and their families, like the American Academy of Neurology.