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Serene Branson, the CBS reporter who looked like she was having an on-air stroke after the Grammys on Sunday, revealed that she has been suffering from migraine headaches since childhood – and doctors say the chronic condition is exactly what caused her to lapse into gibberish during a live report.

A migraine is a common type of headache that can cause significant pain for hours or even days, the Mayo Clinic said on its website. They tend to appear in childhood, adolescence or early adulthood and are caused by abnormal brain activity, which can be triggered by stress, alcohol, certain foods, bright lights and other environmental factors.

The are the several types of migraine headaches. The kind Branson suffered from is called a “complex migraine.” This type causes symptoms such as weakness, loss of vision or difficulty speaking.

According to Harvard Health Publications, complex migraines may also be mistaken for a stroke – which is why many people thought Branson had suffered one.

In an interview Thursday, the reporter said she "started to get a really bad headache" but assumed she was just tired.

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"I started to think, the words on the page are blurry and I could notice that my thoughts were not forming the way they normally do,” she said. “As soon as I opened my mouth I knew something was wrong.”

Fox News Medical A-Team member Dr. Marc Siegel told Fox News that the extreme side effects of what happened to Branson are not common.

“This is a very uncommon form of migraine, less than five percent come with what's called neurological feature, where you have numbness in your hands or your face like she reported, or problems finding the words,” Siegel said.

Siegel explained that although there are various reasons for complex migraines, neurologists do not know them all.

“It could have been either increased electrical activity in the part of the brain, or some spasm in that area of the brain,” he said. “Neurologists are not sure, but when you have that increased activity or spasm, you have what looks like a stroke but it lasts briefly.”

It’s estimated that 28 million Americans suffer from migraine headaches, with most of them having these common symptoms:

- Moderate to severe pain, which may be worse on one side of the head

- Head pain with a pulsating or throbbing quality

- Pain that worsens with physical activity

- Nausea with or without vomiting

- Sensitivity to light and sound

- Blurred vision

- Seeing stars or zig-zag lines

While migraines are still a mystery in some aspects – there is a genetic element. More women are affected by these chronic headaches than men, and they also tend to run in families.

Siegel said that what happened to Branson can be an example for others.

“It's a wake-up call for viewers. If you're not feeling well, don’t ignore it. Go see a doctor,” he said.

After Branson’s on-air scare, she was checked out by paramedics, and sent home. But, according to the Mayo Clinic, someone should seek medical treatment immediately if they have any of the following signs or symptoms:

- An abrupt, severe headache like a thunderclap

- Headache with fever, stiff neck, rash, mental confusion, seizures, double vision, weakness, numbness or trouble speaking

- Headache after a head injury, especially if the headache gets worse

- A chronic headache that is worse after coughing, exertion, straining or a sudden movement
- New headache pain if you're older than 50

Branson said even though she’s had migraines for most of her life, she had never suffered an episode like this one before. 

Click here to read more about migraines from the Mayo Clinic.

The Associated Press contributed to this report.