Here’s a stroke fact that may surprise you: Strokes that cause sudden numbness on one side of the body, slurred speech, dizziness, vision problems or other well-known symptoms aren’t the most common kind. That unfortunate distinction belongs to silent strokes.

A silent stroke may fly under your radar because it doesn’t cause any of the symptoms we typically associate with strokes — those symptoms that serve as a warning to seek medical attention right away.

According to the American Heart Association, these understated strokes affect an estimated 8 million to 11 million people in the US every year. That’s 10 times more than symptomatic strokes. So, what is a silent stroke, and what can you do to prevent it?

The silent treatment

Silent strokes have a lot in common with its more familiar, symptomatic cousins.

Like ischemic strokes — the most common type of stroke — most silent strokes occur when blood clots block a blood vessel to the brain. That prevents oxygenated blood from reaching the organ, causing brain cells in the affected area to die.

Unlike symptomatic strokes, however, silent strokes cause brain damage in areas that don’t control important functions, such as arm or leg movement. That’s why a silent stroke may go unnoticed.

Silent and symptomatic strokes share risk factors, including:

• Certain forms of heart disease, including atrial fibrillation — the most common type of abnormal heart rhythm
• Diabetes
• High blood pressure
• Smoking
• Unhealthy cholesterol levels

As with symptomatic strokes, your risk for a silent stroke increases as you age. Twenty-five percent of people older than 80 have had at least one silent stroke, according to the American Heart Association/American Stroke Association.

How can you tell if you’ve had a silent stroke?

If you experience a silent stroke, you probably won’t find out until well after the fact. That’s because, in the absence of symptoms, many people don’t learn they’ve had one or more silent strokes until they undergo a brain scan to investigate other issues, such as memory loss or headaches.

During such tests, physicians may find evidence of past silent strokes, such as scar tissue or small, bleeding blood vessels.

In some cases, silent strokes cause subtle symptoms, but they’re easy to miss and may go unreported. These symptoms include:

• Memory problems
• Minor mood changes
• Temporary balance disruption

Whether you notice concerning signs or evidence emerges from a brain scan, it’s important to see your primary care physician (PCP) or a neurologist about a suspected silent stroke. That’s because this type of stroke can increase your risk for symptomatic strokes and dementia.

Addressing stroke risk factors can help you avoid those complications.

Stroke prevention tips

Whether you’ve had a stroke — silent or otherwise — and want to prevent another, or you want to avoid a first stroke, you have the power to reduce your risk.

Perhaps the most important stroke-related statistic to know is that as many as 80% of strokes are preventable, according to the Centers for Disease Control and Prevention. With that fact for inspiration, follow these tips to help prevent a first or second stroke: 

• Consult the expert. Your PCP is your partner in stroke prevention. Conditions that can increase your risk for a stroke, such as high blood pressure, diabetes and unhealthy cholesterol levels, may not have symptoms. That’s why it’s important to see your PCP at least once per year so they can check for those conditions, diagnose them early and refer you to a specialist, if necessary. The sooner you start treatment, the better.
• Follow the plan. Your PCP and specialists can prescribe medications and lifestyle changes, but that’s only half of the solution — it’s up to you to follow the experts’ instructions so you can reap the benefits of managing stroke-related chronic conditions.
• Get to (and maintain) a healthy weight. Being overweight or obese increases your stroke risk. To reach and remain at your target weight, takes regular exercise — aim for at least 30 minutes of moderate-intensity aerobic exercise five days per week — and healthy eating. A good way to accomplish the latter is by following the Mediterranean diet, which includes lots of fruits and vegetables, whole grains, beans, nuts, and moderate amounts of dairy products, fish and poultry.
• Stamp out smoking. Smoking damages blood vessels and contributes to the accumulation of plaque inside them. That can lead to stroke-inducing blood clots.If you smoke, quitting is one of the most effective ways to reduce your stroke risk.

Nationally accredited stroke care is closer than you think. Learn about stroke services at Tanner Health System.