When Andrea Syron began noticing a buzzing in her ear—that later grew to a strange “whooshing”—she knew something was wrong. But for months, doctors told her it was just allergies, a bad cold, or fluid trapped in her ear.
It wasn’t until the 36-year-old actress and model saw an ear-nose-and-throat doctor, and underwent imaging scans, that she got a correct diagnosis: an irregularity in the arteries lining her brain, called an ateriovenous malformation (AVM), that was causing the blood vessels above her ear to pulsate.
“I went for a CT scan and when it came back they saw a shadow behind my right ear,” Syron, who lives in Grand Blanc, Michigan, told the Daily Mail. “I had an MRA scan and then they discovered I had an AVM.”
Syron was relieved to know that she “wasn’t crazy,” but was faced with a new worry: AVMs can be extremely dangerous. People who have these irregular blood-vessel connections are at increased risk of a fatal brain bleed, blood clot, or stroke—often with little or no warning beforehand.
Luckily, AVMs are treatable if doctors can identify them before one of those complications occurs. Syron had surgery two months ago to repair about half of the irregularities in or around her brain, and she may need another operation in the future. Now, the Daily Mail reports, Syron is raising awareness about the condition that turned her into a self-described “ticking time-bomb,” and the symptoms that were missed and misdiagnosed by her doctors.
To be clear, AVMs aren’t common; it’s estimated they affect about one in every 2,000 to 5,000 people. Even so, they can happen to anyone—and getting a diagnosis, as Syron was finally able to do, can be life-saving. Here are a few things to know.
They don’t usually cause symptoms
In many ways, Syron is lucky that one of her AVMs was located just above her ear, said Dr. Do.
“She was probably able to notice that fast-flowing stream of blood because it was right next to her hearing apparatus,” he said. “A lot of people don’t have symptoms at all until these things cause problems—and the number one problem they cause is bleeding.”
That doesn’t mean that everyone else with an AVM is doomed, though. Headaches, vision or nerve problems, and seizures can also be signs of an otherwise hidden AVM, and should always be taken seriously by physicians, said Do. And even if a brain bleed does occur, most are not fatal—although seeking treatment right away is very important, and some do cause permanent neurological damage.
Surgery can be very effective
If doctors can identify and diagnose an AVM before it’s too late, they can also treat it with surgery or embolization—a process in which parts of blood vessels are blocked off—or a combination of both. In Syron’s case, surgeons inserted a catheter into a large artery in the actress’s groin, and threaded it through her body, around her heart, and into the lining of her brain, the Daily Mail reported.
They then injected onyx, an embolization material, to close off the abnormal connections in her veins and arteries. Doctors only intended to close off three of Syron’s ten fistulas, or abnormal openings, “but the surgery was going so well my doctor, Dr. Boyd Richards, decided he was able to close off three more,” she said.
Do said it’s important for people with AVMs to know that a diagnosis is not a death sentence.
“We have very good techniques and surgical procedures to treat and cure these problems and prevent life-ending or life-altering strokes,” he said.
They’re often congenital, but not usually hereditary
Scientists don’t know why AVMs affect some people and not others. They are usually congenital, which means they form even before a person is born. And according to the American Stroke Association, they’re not usually inherited from parents or passed onto children.
Still, cases of AVMs in families have been reported. If you have a family history of hemorrhagic stroke (stroke due to bleeding), Do said it’s not a bad idea to mention this to your doctor and ask if you should be monitored with specific screenings.
“Your primary care doctor might not know much about this topic,” he added, “so you may have to be referred to a neurosurgeon or an interventional neuroradiologist who deals with and treats these problems.”
A healthy lifestyle is a good defense
Eating well, exercising, not smoking, and otherwise taking care of yourself won’t prevent AVMs from forming or make existing ones go away—but it can help keep your blood pressure in a healthy range, which may reduce the risk of an AVM rupturing, says Dr. Do.
“High blood pressure is a common risk factor for a lot of vascular diseases,” he explained. “I don’t think it’s been proven that high blood pressure could increase the chances of an AVM rupturing, but it makes sense that the vessels could weaken under higher pressure.”
Plus, he adds, staying fit and healthy—and getting regular physicals—can help you and your doctor stay in tune with your body and recognize anything out of the ordinary. “A good lesson here is to listen to your body, alert your doctor to any new symptoms, and get a second opinion if you still aren’t satisfied,” he said.
This article first appeared on Health.com.