Both may occur suddenly and without any warning, but there are key differences between a stroke and aneurysm. Here’s how to tell each life-threatening condition apart.

The terms “stroke” and “aneurysm” are sometimes used interchangeably, but these two serious conditions have some important differences.

A stroke occurs when there’s a ruptured blood vessel in the brain or blood supply to the brain has been blocked. An aneurysm is the result of a weakened artery wall.

Aneurysms cause bulges in your body, which may also rupture and subsequently bleed. They can affect any part of the body, including the brain and heart.

Keep reading to learn more about identifying and treating strokes and aneurysms.

There are two main types of stroke: ischemic stroke and hemorrhagic stroke. They each have a distinct cause.

An aneurysm in the brain, or cerebral aneurysm, usually stems from damage to the artery. It can be caused by trauma, an ongoing health condition such as high blood pressure or drug abuse, or a vascular problem that you’ve had since birth.

Ischemic stroke

An ischemic stroke is the most common type of stroke, accounting for about 87 percent of all strokes. It occurs when an artery in the brain or an artery carrying blood to the brain becomes blocked. The blockage may be a blood clot or a narrowing of the artery due to plaque buildup.

Plaque in an artery is made up of fats, cells, and low-density lipoprotein (LDL). LDL is also known as “bad” cholesterol.

When arteries anywhere in the body become narrowed by plaque or become rigid because of high blood pressure or other health problems, the condition is called atherosclerosis. You may have heard it described as “hardening of the arteries.”

When this happens, blood flow either stops completely or is reduced to the point where the organs and tissue relying on that blood supply become starved and injured.

Hemorrhagic stroke

A hemorrhagic stroke isn’t related to blockage in an artery. It’s a bleeding event in which an artery ruptures. Blood either stops flowing altogether through that artery, or blood flow is reduced as blood leaks out through the new opening in the artery wall.

A hemorrhagic stroke may occur due to an irregular formation of blood vessels. This is called an arteriovenous malformation (AVM). These irregular blood vessels can rupture and spill blood into the brain.

The most common cause of a hemorrhagic stroke is the bursting of a small artery due to high blood pressure. It can also be caused by a cerebral aneurysm. A blood vessel wall becomes weak because it’s bulging outward. Eventually, an aneurysm can burst.

The hole in the artery wall means blood flow is reduced farther downstream. That causes blood to spill into the tissue surrounding the artery.

Any time blood flow to a part of the brain is disrupted, the event is called a stroke.

Cerebral aneurysm

In addition to an AVM, other genetic health conditions, such as connective tissue disorders, can lead to an aneurysm in the brain. An aneurysm can also develop when the arterial wall is damaged.

High blood pressure and smoking both strain blood vessels. Atherosclerosis, infections, and trauma to the head, such as concussion, can also lead to an aneurysm.

Both a stroke and an aneurysm that bursts can come on suddenly without any warning. The symptoms will vary. The kind of emergency treatment you should receive will also depend on whether it’s a stroke or an aneurysm.

Regardless of the cause, a fast response to symptoms is essential.

Stroke symptomsAneurysm symptoms
sudden, intense headache headache (worst headache of life)
numbness or tingling on one side of the face or bodynumbness in one or both limbs
weakness in arms or legs or face, especially on one side weakness in one or both limbs
trouble with balance or coordinationmemory issues
vision problemsvision problems or hearing problems
language issues and slurring of wordsN/A

Not all of the stroke symptoms will be present. If one or a few signs develop quickly, you should assume you are having a stroke. Call 911 immediately if you suspect you’re having a stroke.

You won’t usually have symptoms if you have an aneurysm unless the aneurysm bursts. If an aneurysm bursts, you’ll get a sudden and terrible headache. You may also get sick to your stomach and vomit. The event may also make you very tired or can even cause you to go into a coma.

Strokes and aneurysms share many of the same risk factors:

  • When high blood pressure is uncontrolled, you’re at increased risk for a stroke and an aneurysm.
  • Smoking is also a major risk factor for strokes and aneurysms, because of the damage it does to your blood vessels.
  • A previous history of stroke or heart attack also increases your odds of having a cerebrovascular event.
  • Women have a slightly higher risk than men of developing a cerebral aneurysm or a stroke.
  • Advancing age increases your risks for both events.
  • A family history of aneurysms or strokes may also put you at a higher risk for these events.

If you’ve had one aneurysm, your odds of having another are also higher.

Sharing your symptoms and personal medical history with your doctor will help them form a diagnosis and treatment plan.

CT and MRI scans can help your doctor diagnose an aneurysm or stroke. A CT scan shows the location of bleeding in the brain and areas of the brain affected by poor blood flow. An MRI can create detailed images of the brain. In some cases, your doctor may order both an MRI and a CT scan, as well as other imaging tests.

Your doctor will determine the best treatment based on the severity of your stroke or aneurysm and your medical history.

Ischemic stroke

If you had an ischemic stroke and made it to the hospital within a few hours of symptoms starting, you may receive a medication called tissue plasminogen activator (TPA). This drug helps break up a clot. Your doctor can also remove a clot from a blood vessel.

Hemorrhagic stroke

For a hemorrhagic stroke, you may need surgery to repair the damaged blood vessel. Your surgeon may use a special clip to secure the part of a blood vessel that ruptured. They can do this during open surgery, which involves cutting into your skull and working on the artery from the outside.

Cerebral aneurysm

If you have a small aneurysm that hasn’t ruptured, your doctor may treat it with medications and a watch-and-wait approach. This means they take images of the aneurysm periodically to make sure it hasn’t grown. If it has, then you may need a procedure.

A ruptured aneurysm is a life-threatening condition, with high mortality rates, particularly in the first days of the event. Many people who survive a ruptured aneurysm have effects that linger for the rest of their lives. Brain damage due to bleeding is irreversible.

Aneurysms that have not ruptured may still need treatment — based on their size, location, and shape — as these factors determine the likelihood of rupturing in the future.

The outlook for people who have a stroke is much more varied. An ischemic stroke can be either be devastating or relatively mild. Some ischemic stroke survivors have few if any long-term symptoms. A hemorrhagic stroke, on the other hand, is more likely to be deadly or leave a person with cognitive or physical disabilities.

The location of the stroke and time that goes by before blood flow is restored makes a difference in your recovery. Rapid treatment may make the difference between being able to walk and talk normally or requiring a walker and years of speech therapy.

A foolproof way to prevent an aneurysm or stroke doesn’t exist. You can, however, make sure your blood pressure is under control. Here are some ways to help control your blood pressure:

If you smoke, talk with your doctor about strategies to quit smoking.

Living a healthy lifestyle can reduce your risk for strokes or aneurysms, but if you or a loved one has recently dealt with one of these life-altering situations, help is available.

Check for rehab facilities in your area. Many of them offer physical therapy and lifestyle education to help with the healing process.