The Difference Between Silent and Mini-Stroke

Although they sound similar, there is a difference between silent stroke and mini-stroke. First, though, let's talk about stroke in general. 

Stroke is a health emergency that occurs when blood supply to a part of the brain is reduced or interrupted. When that happens, the affected area can't get the blood, oxygen, and nutrients it needs, and brain cells die.

The brain is an extremely complex organ that controls various body functions. When a stroke reduces blood flow to a particular region of the brain, it can impact how body systems work.

A stroke can involve the arteries leading to and within the brain. It is the fifth most common cause of death and a leading cause of disability in the United States.

This article outlines basic risk factors for stroke, how to distinguish between mini-strokes and silent strokes, and why these two types of stroke should not be ignored.

Woman with headache sitting down with hand to her head

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Stroke Risk Factors

Risk factors for stroke include:

  • Age: The chance of having a stroke approximately doubles for each decade of life after age 55. While stroke is common among people over age 75, a lot of people under 65 also have strokes.
  • Heredity (family history): Your stroke risk may be greater if a parent, grandparent, sister, or brother has had a stroke. 
  • Race: African-Americans are at a greater risk of death from a stroke than others. This is partly because Black people are also at a greater risk of high blood pressure, diabetes, and obesity.
  • Sex: Each year, women have more strokes than men, and stroke kills more women than men. Use of birth control pills, pregnancy (and a history of complications like preeclampsia, eclampsia or gestational diabetes), oral contraceptive use, smoking, and post-menopausal hormone therapy may increase stroke risk for women. 
  • Prior stroke, mini-stroke, or heart attack: If you've experienced a stroke, you're more than 20 percent more likely to have another one. If you've had a heart attack, you're at a higher risk of having a stroke, too.
  • Other conditions: High cholesterol, high blood pressure, diabetes, and bleeding or blood clotting disorders are other risk factors for stroke.

Silent Strokes

If someone has a stroke without realizing it, it's called a silent stroke. Usually, evidence of a silent stroke is found while undergoing a magnetic resonance imaging (MRI) test for another condition. They often do not even remember having any symptoms.

One study showed that by the age of 69, approximately 10% to 11% of people who consider themselves stroke-free have suffered at least one stroke that can be seen on MRI.

Silent strokes cause no obvious loss of function, because other areas of the brain are able to compensate for the damaged one. However, they are a strong risk factor for a more severe stroke later on.

Mini-Strokes

A mini-stroke, on the other hand, is a brief, but discrete and memorable event. During a mini-stroke, a patient experiences symptoms of a stroke for a few minutes to a few hours. By definition, the symptoms of a mini-stroke disappear in less than 24 hours. Mini-strokes are also referred to as transient ischemic attacks (TIAs).

TIAs are "warning strokes" that produce stroke-like symptoms but no lasting damage. TIAs are strong predictors of stroke. A person who's had one or more TIAs is almost 10 times more likely to have a stroke than someone of the same age and sex who hasn't. 

Recognizing and treating TIAs can reduce your risk of a major stroke. TIA should be considered a medical emergency and followed up immediately with a healthcare professional.

Summary

Mini-strokes and silent strokes may not seem as serious as full-blown strokes, but they should still cause concern because both conditions indicate an increased risk. When it comes to stroke in general, prevention is key. Understanding your risk factors–and taking steps to modify your lifestyle accordingly–can help you avoid having a stroke.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Leading causes of death. Last reviewed October 30, 2020.

  2. Centers for Disease Control and Prevention. Stroke risk. Reviewed January 17, 2017.

  3. Johns Hopkins Medicine. 3 Ways to avoid a second stroke.

  4. Das RR, Seshadri S, Beiser AS, et al. Prevalence and correlates of silent cerebral infarcts in the Framingham offspring study. Stroke. 2008;39(11):2929-35. doi: 10.1161/STROKEAHA.108.516575

  5. American Stroke Association. TIA (Transient ischemic attack).

By Jose Vega MD, PhD
Jose Vega MD, PhD, is a board-certified neurologist and published researcher specializing in stroke.