Prompt diagnosis and care for a stroke is vital. If a doctor suspects a stroke based on medical history and a physical exam, imaging and other tests can help determine the type, location, and severity.

Someone has a stroke every 40 seconds in the United States, according to the Centers for Disease Control and Prevention (CDC). Stroke affects over 795,000 people in the United States each year and is the leading cause of serious long-term disability.

A stroke is a medical emergency. Early diagnosis and treatment are essential for preventing complications or death. Doctors can use several different tests to help diagnose a stroke.

The first important step for a doctor diagnosing stroke is to take your medical history. This can help them get an idea about the type of stroke you may have and its severity. They’ll ask you or a member of your family about things such as:

The doctor will also do a physical exam where they will check your vital signs and level of alertness. They’ll also look for physical signs of a stroke, such as weakness, trouble walking, or difficulty speaking.

The physical exam will also include a neurological exam to test how well your nervous system is working. The doctor may test your reflexes, ask you questions, or ask you to do some simple tasks.

Detailed imaging allows doctors to see your brain and its blood vessels. This helps them determine whether your stroke is due to a blockage (ischemic stroke) or a burst blood vessel (hemorrhagic stroke). It can also help them determine the stroke’s location and severity.

CT scan

A CT scan uses X-rays to create images of your brain and is one of the first tests you’ll have after a suspected stroke. Because it can show bleeding in the brain, it can help a doctor confirm or rule out a hemorrhagic stroke.

MRI scan

An MRI scan uses radio waves and strong magnets to make images of your brain. It can show brain changes due to stroke and identify bleeding or blood flow problems.

You may receive an MRI scan instead of or in addition to a CT scan.

Doctors may also use a special type of MRI called a diffusion-weighted MRI to help detect ischemia in the brain. This type of MRI can help detect ischemic strokes early, even small ones.


Angiography uses a special dye to look at blood flow in your brain, which can help a doctor find blocked vessels or continued bleeding in the brain. Images can be made using either CT (CT angiography) or MRI (MR angiography).

Perfusion scans

Perfusion scans use a special dye or tracer to look at how blood is being taken up in your brain. They can help a doctor find areas that aren’t receiving enough blood due to an ischemic stroke.

Doctors can perform perfusion scans using CT, MRI, or PET imaging technology.

Blood tests can’t confirm a stroke diagnosis. However, they can give doctors valuable information about the potential cause of your symptoms. Tests include:

An electrocardiogram (EKG) measures the electrical activity of your heart. It can help a doctor see if your stroke was due to atrial fibrillation (AFib).

AFib is a type of arrhythmia that causes your heart to beat irregularly and often too fast. It increases your risk of potentially serious blood clots. Experts estimate AFib causes 1 in 7 strokes.

A doctor may send you home with an EKG monitor for days or even weeks. This can help diagnose AFib that wasn’t detected earlier or while in hospital.

A lumbar puncture collects a sample of cerebrospinal fluid (CSF) from around your spinal cord. This sample can then undergo analysis in a lab.

A doctor may order a lumbar puncture if they suspect that a hemorrhagic stroke has occurred and other tests have been inconclusive. Changes in CSF color or red blood cells in the CSF can signal bleeding in the central nervous system.

A stroke is a medical emergency that requires immediate treatment. After confirming the type, location, and severity of your stroke, your healthcare team will start treatment. These factors also determine which treatments to use.

Treatment for ischemic stroke may include:

Treating hemorrhagic stroke may involve a procedure to repair the burst blood vessel. Blood pressure medication can help lower the strain on your blood vessels during treatment.

Depending on the type of stroke, your neurologist may want to keep your blood pressure high for 1–2 days to ensure proper blood flow to the brain.

Recovery from a stroke varies by person and can take weeks, months, or even years. The duration often depends on the location and severity of the stroke as well as how long it took to receive treatment. Some people may recover completely, while others may have lasting disabilities. Rehabilitative care is often necessary during recovery.

What is the fastest way to check for a stroke?

Recognizing the warning signs of a stroke is the fastest way to check for stroke and seek necessary care. To check for a stroke, use the FAST method.

Suspect a stroke? Act FAST

  • Face: Ask the person to try to smile. Does one side of the face droop?
  • Arms: Ask the person to raise both their arms. Does one arm start to drift downward?
  • Speech: Ask the person to say a simple sentence. Is speech difficult or slurred?
  • Time: Early treatment is vital. If you see any of the signs above, call 911 or your local emergency services.
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How long after a stroke can it be detected?

Imaging can detect a stroke minutes to hours after it’s happened. The timing can depend on the type of imaging. For example, diffusion-weighted MRI can find an ischemic stroke within minutes, even when conventional CT or MRI scans don’t yet show signs of stroke.

What can mimic a stroke?

Many conditions may mimic stroke symptoms, including:

Doctors can use several tests to help to diagnose stroke. A medical history and physical exam followed by imaging of the brain can help them identify the type, location, and severity of the stroke and to plan treatment.

Blood tests can’t diagnose a stroke alone but can provide helpful information about the potential cause of your symptoms. Doctors may also use EKG and lumbar puncture in certain situations.

Prompt diagnosis and treatment of a stroke is vital in preventing complications. If you suspect that you or another person is having a stroke, call 911 or your local emergency services.