What is an ischemic stroke?
An ischemic stroke is a life-threatening medical condition that happens when there’s a lack of blood flow to a part of your brain. These usually happen because of blood clots, but they can also happen for other reasons.
Ischemia (pronounced “iss-key-me-uh”) is when cells in your body don’t have enough blood flow, which causes them to die. When this happens in areas of your brain, you lose the abilities controlled by those brain areas. If those brain cells die, that can lead to permanent brain damage or even death.
IMPORTANT: A stroke is a life-threatening emergency condition where every second counts. If you or someone with you has symptoms of a stroke, you need to IMMEDIATELY call 911 (or your local emergency services number). The longer it takes to receive care, the more likely a stroke will cause permanent brain damage or death.
To recognize the warning signs of a stroke, remember to think FAST:
- F is for face. Ask the person to smile. Look for a droop on one or both sides of their face, which is a sign of muscle weakness or paralysis.
- A is for arm. A person having a stroke often has muscle weakness on one side. Ask them to raise their arms. If they have one-sided weakness (and didn’t have it before), one arm will stay higher while the other will sag and drop downward.
- S is for speech. Strokes often cause a person to lose their ability to speak. They might slur their speech or have trouble choosing the right words.
- T is for time. Time is critical, so don’t wait to get help! If possible, look at your watch or a clock and remember when symptoms start. Telling a healthcare provider when symptoms started can help the provider know what treatment options are best for you.
What’s the difference between an ischemic stroke and a hemorrhagic stroke?
An ischemic stroke involves a blockage in blood flow in your brain. A hemorrhagic stroke involves bleeding in or around your brain that disrupts blood flow.
Who does it affect?
Ischemic strokes are most common in people who have a problem that affects how blood circulates in their brain. Those problems are usually age-related, so ischemic strokes are more common as people get older.
About two-thirds of all strokes happen in people over the age of 65. However, younger individuals are still at risk for ischemic strokes. There are also certain medical conditions that can either cause these kinds of strokes or make them more likely to happen.
How common is an ischemic stroke?
Strokes are very common. Worldwide, strokes rank second among the top causes of death. In the United States, they rank fifth. Strokes are also one of the leading causes of disability worldwide. Ischemic strokes make up about 85% of all strokes.
How does this condition affect my body?
An ischemic stroke is the brain’s version of a heart attack. When you have an ischemic stroke, part of your brain doesn’t get enough blood. Your brain cells need blood flow to supply them with oxygen, vital nutrients and more.
Different areas of your brain control specific abilities. The symptoms of a stroke happen because the brain cells in the affected brain area aren’t getting enough blood flow, so they stop working like they should and start to die. If they don't get blood flow back fast enough, too many brain cells in that area die off, and you permanently lose any abilities they controlled. In severe cases or cases that go untreated for too long, this can also cause death.
Symptoms and Causes
What are the symptoms of an ischemic stroke?
The symptoms of an ischemic stroke can involve one or more of the following:
- One-sided weakness or paralysis.
- Aphasia (difficulty with or loss of speaking ability).
- Slurred or garbled speaking (dysarthria).
- Loss of muscle control on one side of your face or facial droop.
- Sudden loss — either partial or total — of one or more senses (vision, hearing, smell, taste and touch).
- Blurred or double vision (diplopia).
- Loss of coordination or clumsiness (ataxia).
- Dizziness or vertigo.
- Nausea and vomiting.
- Neck stiffness.
- Emotional instability and personality changes.
- Confusion or agitation.
- Memory loss (amnesia).
- Headaches (usually sudden and severe).
- Passing out or fainting.
Transient ischemic attack (TIA)
A transient ischemic attack (TIA) — sometimes called a “mini-stroke” — is like an ischemic stroke, but the effects are temporary and usually go away on their own. These are often warning signs that a person has a very high risk of having a true stroke soon. Because of that, a person who has a TIA needs emergency medical care as soon as possible.
What causes ischemic strokes?
Ischemic strokes usually involve certain processes. These are:
- Formation of a clot in your brain (thrombosis).
- A fragment of a clot that formed elsewhere in your body that breaks free and travels through your blood vessels until it gets stuck in your brain (embolism).
- Small vessel blockage (lacunar stroke).
- Unknown reasons (these are cryptogenic strokes; the word “cryptogenic” means “hidden origin”).
Blood clots and other forms of ischemia can happen for many reasons, such as:
- Clotting disorders.
- Atrial fibrillation (especially when it happens due to sleep apnea).
- Heart defects (atrial septal defect or ventricular septal defect).
- Microvascular ischemic disease (which can block smaller blood vessels in your brain).
- Fat emboli, which are clusters of fat particles circulating in your blood that get stuck in blood vessels in your brain.
- Infected tissue that gets into your bloodstream and travels to your brain, where it gets stuck and blocks a blood vessel (this is a major complication of sepsis, a deadly overreaction of your immune system to an infection spreading in your body).
There are other conditions and circumstances that might not cause a stroke directly, but that still contribute to your risk of having a stroke or the severity of a stroke you have. These include:
- Alcohol use disorder.
- High blood pressure (this can contribute to blood vessel damage that makes an ischemic stroke more likely to happen).
- High cholesterol (hyperlipidemia).
- Type 2 diabetes.
- Smoking and other forms of tobacco use (including vaping and smokeless tobacco).
- Recreational drug use or misuse of prescription drugs.
Are ischemic strokes contagious?
Ischemic strokes aren’t contagious and can’t spread from one person to another.
Diagnosis and Tests
How are ischemic strokes diagnosed?
A healthcare provider can diagnose a stroke using a combination of a neurological examination, diagnostic imaging and other tests. To do a neurological examination, a provider will ask you to move your hands, feet, arms, legs, eyes and head in specific ways, and answer some questions. As you perform these tasks or answer these questions, the provider will look for signs or clues that indicate a problem with how different areas of your brain are working. That can help them determine if you’re having a stroke and may even hint at where in your brain it’s happening.
What tests will be done to diagnose an ischemic stroke?
The most common tests that happen when a healthcare provider suspects an ischemic stroke include:
- Computerized tomography (CT) scan.
- Lab blood tests (looking for signs of infections or heart damage, checking clotting ability and blood sugar levels, testing how well kidneys and liver function, etc.).
- Electrocardiogram (abbreviated ECG or EKG) to make sure that a heart issue isn’t the source of the problem.
- Magnetic resonance imaging (MRI) scans.
- Electroencephalogram (EEG), though less common, can rule out seizures or related problems.
Management and Treatment
How are ischemic strokes treated?
The highest priority with ischemic stroke is restoring circulation to the affected brain areas. That’s because restoring circulation quickly can limit the damage and preserve brain tissue. The less permanent brain damage you have, the more likely you’ll keep all or most of the abilities you had before the stroke.
Is there anything I shouldn’t eat or drink with this condition?
If you’re at risk for a stroke, your healthcare provider may recommend changing your diet to maintain or lower your blood pressure, which can also help in managing blood sugar and cholesterol. Changing your diet like this includes avoiding or limiting:
- Beverages that contain caffeine, such as coffee, tea, soft drinks, etc.
- Foods containing a lot of salt or sodium, which can increase blood pressure (you should consume no more than 2 grams per day, or less if your healthcare provider recommends a lower amount).
- Foods high in refined sugars.
- Highly processed foods like deli meats.
- Foods that are high in saturated fats, such as fried foods, etc.
- Alcohol or recreational stimulant drugs (marijuana, cocaine, amphetamines/methamphetamine, etc.).
What medications or treatments are used?
The treatments for ischemic stroke depend strongly on how long it’s been since the stroke symptoms started. That’s one of the main reasons why it’s so important not to delay going to the emergency room if you have stroke symptoms.
Thrombolytic drugs are an option within the first three hours to four and a half hours after stroke symptoms start. These medications dissolve existing clots (their name is a combination of the Greek words “thrombus,” which means “clot,” and “lysis,” which means “loosening/dissolving”). However, they’re only an option within that three- to four-and-a-half-hour time frame because after that, they increase the risk of dangerous bleeding complications.
Endovascular mechanical thrombectomy
This is a procedure to remove a clot from your brain using a catheter-based approach. Thrombectomy means “surgery to remove a blood clot.” The term “endovascular” means “inside blood vessels.” Thrombectomy procedures are also time-sensitive, and these usually are only possible in the first 24 hours after symptoms start.
During this procedure, a healthcare provider will insert a small, tube-like device called a catheter into a major blood vessel somewhere on your body. Once it’s inside the vessel, the provider will then thread the catheter up to the clot in your brain. When the tip of the catheter reaches the clot, it can either suck up the clot directly or break it apart and suck up the fragments.
Supportive treatments and other methods
Some examples include:
- Mild hypothermia: Your brain cells die more easily when your body temperature is higher. Lowering your body temperature makes brain cells more durable against stroke-related damage.
- Blood sugar management: Your brain cells need glucose, a type of sugar, for fuel. Too little glucose in your blood slows down your brain’s recovery. However, too much glucose in your blood can also cause problems with your brain’s self-repair abilities.
- Blood thinners: This involves giving you medications that keep your blood from clotting too easily. This is only an option with ischemic strokes that happen due to blood clots, as these can make hemorrhagic strokes much worse.
- Oxygen: A stroke reduces the available oxygen in your blood, which means there’s less oxygen available for your brain to use. Giving you supplemental oxygen to breathe makes it easier for your body to supply oxygen to your brain.
It’s common for people to have some lingering effects from a stroke in the days and months that follow. For many, the effects of a stroke will get slightly worse in the first few days after the stroke, and then they’ll improve.
Because it’s common for people to have lingering problems from a stroke, rehabilitation and therapy methods are common to help people recover from a stroke. In some cases, therapy simply helps you return to how you were before your stroke. In other cases, this kind of therapy can help you relearn how to do certain things.
Your brain has a remarkable ability called “neuroplasticity” (pronounced “new-row-plass-tiss-it-ee”). That means your brain can adapt and change when it needs to. In some cases, your brain will “re-map” an ability, transferring control of that ability to an undamaged part of the brain. Many stroke therapy methods take advantage of that ability and speed up the process.
Stroke rehabilitation can take many forms, including:
- Speech therapy: This type of therapy focuses on the parts of your brain that manage your ability to speak and understand others when they’re talking. It also can help if you have any kind of weakness or loss of ability to control muscles in your mouth and throat. Speech therapy can help with speaking ability, as well as with breathing, swallowing, and eating or drinking.
- Physical therapy: This therapy approach focuses on improving muscle strength and control, especially with muscles in your arms, hands, legs and feet. This type of therapy can help you regain abilities like walking, dressing yourself or eating. It can also help you adapt if you have a permanent or long-term loss of an ability.
- Cognitive therapy: This kind of therapy helps you work on strengthening your mind, especially your ability to think, concentrate and remember.
Other treatments are possible, depending on your case and circumstances. Your healthcare provider is the best person to tell you what kind of treatments can benefit you.
Complications/side effects of the treatment
The possible side effects or complications can change depending on where a stroke happens in your brain, the treatments used, your medical history and many other factors. Your healthcare provider can tell you more about the side effects that you can or should expect, and what you can do to manage or even prevent them.
How can I take care of myself or manage the symptoms?
A stroke is a life-threatening medical emergency, which means you shouldn’t try to self-diagnose it. If you have — or someone with you has — stroke symptoms, it’s critical that you immediately call 911 (or your local emergency services number). Any delay in getting treatment for a stroke increases the risk of permanent brain damage or even death.
How soon after treatment will I feel better?
How long it takes to feel better after treatment and the time to recover after a stroke can vary from person to person. That’s because many factors play a part in how you feel over time. If you have questions about the likely timeline for your treatment and recovery, your healthcare provider is the best person to answer that question and give you information that is most accurate for your situation.
How can I reduce my risk of having an ischemic stroke or prevent them entirely?
There are many things you can do to reduce your risk of having an ischemic stroke. While this doesn’t mean you can prevent a stroke, it can lower your risk: Actions you can take include:
- Improve your lifestyle. Eating a healthy diet and adding exercise to your daily routine can improve your lifestyle. You should also make sure to get enough sleep (the recommended amount is seven to eight hours).
- Avoid risky lifestyle choices or make changes to your behaviors. Smoking and tobacco use, including vaping, recreational drug use or prescription drug misuse, and alcohol misuse can all increase your risk of having a stroke. It’s important to stop these or never start them. If you struggle with any of these, talking to your healthcare provider is important. Your provider can offer you guidance and resources that can help you change your lifestyle to avoid these behaviors.
- Manage your health conditions and risk factors. There are several conditions, such as obesity, abnormal heart rhythms, sleep apnea, high blood pressure, Type 2 diabetes or high cholesterol, which can increase your risk of having an ischemic stroke. If you have one or more of these conditions, it’s very important that you do what you can to manage them, especially by taking medications — such as blood thinners — as prescribed by your provider. Doing that earlier in life can you avoid severe stroke-related problems later in life.
- See your primary care provider for a checkup or wellness visit annually. Yearly wellness visits can detect health problems — especially ones that contribute to having a stroke — long before you feel any symptoms.
Outlook / Prognosis
What can I expect if I have an ischemic stroke?
If you have a stroke, many factors affect what you can expect. These include, but aren’t limited to, the size of the stroke and the specific areas of the brain it affects. In general, the larger the stroke, the more severe the symptoms. Larger strokes also have a higher risk of an unfavorable outcome. Some strokes can be smaller, but can still be severe if they affect a critical area of your brain. An example of this is a stroke that affects areas of your brain that control your ability to speak. These can severely disrupt your life, but are less likely to be life-threatening.
The more severe an ischemic stroke is, the more likely that you’ll lose — at least temporarily — certain abilities. Larger strokes are also more likely to cause permanent damage or death. That’s why getting medical attention quickly is so important. The faster you get medical attention for stroke symptoms, the better your chances that these effects will be temporary or less severe.
Strokes can happen in very different ways from person to person. While there are many similarities in how strokes happen and the symptoms unfold, not all cases are the same. Because of that, your healthcare provider is the best person to tell you what you can and should expect.
How long does an ischemic stroke last, and when I can I return to school, work or my usual routine?
Even after you receive treatment for your stroke and blood flow returns to the affected brain areas, you may feel lasting effects. Some of these effects are short-term and will get better over the coming days, but others may last for weeks or months before improving. Some effects may be permanent. Your healthcare provider is the best person to tell you how long you should expect to feel the effects of a stroke, but it can still be hard to predict and can vary greatly from person to person.
What’s the outlook for this condition?
The outlook for an ischemic stroke can vary widely from person to person. That’s because many factors can play a role in how this condition affects you. In general, getting care quickly increases the odds that you’ll have a better outcome. Your healthcare provider is the best person to tell you what the outlook is for you based on your specific circumstances.
How do I take care of myself after having an ischemic stroke?
If you have an ischemic stroke, your healthcare provider will provide you with information and resources that can help as you recover. They’ll likely recommend that you take certain kinds of medications, especially blood thinners, to prevent another stroke.
The best things you can do to care for yourself after having a stroke include:
- Take your medications as prescribed. This can help you prevent another stroke from happening.
- See your provider as recommended and go to therapy/rehabilitation appointments. These kinds of visits can be very helpful as you recover after a stroke. Doing your best in these sessions can also speed up your recovery or help you recover more of your abilities than you would otherwise.
- Don’t neglect your mental health. People who have strokes often deal with depression, anxiety and other mental health effects. It’s important to see a healthcare provider for care regarding these effects, too.
- Make recommended lifestyle changes if at all possible. Modifying the way you live your life in small, meaningful ways can make a big difference in preventing another stroke.
When should I see my healthcare provider?
Your healthcare provider will schedule follow-up appointments for you, and you should also call or see them if you notice any changes and symptoms that might have a link to your stroke. You also should talk to them if you notice symptoms or issues that are disrupting your life or routine, even if those symptoms don’t have a connection to your stroke or don’t seem very important.
When should I go to the ER?
You should call 911 (or your local emergency services number) and go to the nearest ER if you experience any symptoms of another stroke (see the FAST criteria at the top of this article to know the symptoms for which you should watch).
You should also go to the hospital if you experience any of the symptoms of dangerous complications that are common after a stroke. The most common complicating conditions include:
Frequently Asked Questions
How serious is an ischemic stroke?
Ischemic strokes are a life-threatening medical emergency. It’s important to immediately get medical care if you notice you have the symptoms of one or if you’re with someone who has those symptoms.
A note from Cleveland Clinic
An ischemic stroke is a life-threatening medical emergency that needs immediate care. These kinds of strokes can have sudden, frightening symptoms. Fortunately, there are many things you can do to prevent these or reduce your risk of them happening.
If you notice you’re having these symptoms or are with someone having them, it’s important to get medical attention right away. With fast medical care, many people recover from an ischemic stroke and will get back most or all of their abilities.
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