When someone has a stroke, every second is crucial. The longer it takes to receive treatment, the more likely it is that damage to the brain will occur. 

"The mantra is 'time is brain,'" explains Dr. James Meschia, a Mayo Clinic neurologist and stroke expert. "The sooner they get treatment, the better patients do."

World Stroke Day is recognized each year on Oct. 29. The aim is to teach the public about stroke risk factors and stroke prevention, and to raise awareness about the warning signs of stroke so people recognize when a loved one may be having a stroke and can take action.

To recognize the warning signs of stroke, Dr. Meschia says remember the acronym, BE FAST:

There are two main types of strokes: ischemic and hemorrhagic. An ischemic stroke happens when there is a loss of blood supply to an area of the brain. A hemorrhagic stroke happens when there is bleeding into the brain when a blood vessel ruptures. Eighty-five percent of all strokes are ischemic.

Globally, 1 in 4 adults over 25 will have a stroke in their lifetime, according to the World Stroke Organization. More than 110 million people in the world have experienced stroke, but thanks to the development of clot-busting drugs and procedures to remove clots using a catheter, outcomes for people who have a stroke are improving.

"The first big treatment revolution happened in the 1990s. And in 1995 we finally closed in on a dose and a time window to give a clot-busting drug known as tissue plasminogen activator or, tPA," says Dr. Meschia. "Then in 2015, the added benefits of mechanical thrombectomy were clearly established. That is where a catheter is inserted, and, under guidance by an X-ray camera, the tip of the catheter is positioned in or near the clot and the clot pulled out. So used in combination or by themselves, thrombolysis and thrombectomy have been major advances in the therapy."

After emergency treatment, most stroke survivors go through a rehabilitation program. Stroke care focuses on helping people recover as much function as possible, with the goal of returning to independent living. The impact of the stroke depends on the area of the brain involved and the amount of tissue damaged.

If the stroke affected the right side of the brain, movement and sensation on the left side of the body may be affected. If the stroke affected the left side of the brain, movement and sensation on the right side of the body may be affected. Brain damage to the left side of the brain may also cause speech and language disorders.

Dr. Meschia encourages stroke victims to realize that the effects of a stroke are worse at the beginning, and that there is hope for rehabilitation.

"One of the important points with stroke is that it is sudden in onset, and often maximally severe at onset," says Dr. Meschia. "There are some exceptions, but I would say about 9 out of 10 are maximally severe at onset. And then, over the course of one to three months with appropriate rehabilitation — be it speech, physical or occupational therapy, or a combination thereof — patients do rally and improve significantly. And it is one of the things to be aware of because sometimes patients and families can feel like giving up. I think that would be tragic because, at least in the short term, the prognosis is favorable for some level of recovery."

Many strokes can be prevented in the first place by minimizing risk factors. Maintaining a healthy body weight, staying physically active and controlling blood pressure reduce the risk of stroke. Other stroke prevention steps include stopping smoking, eating a healthy diet and managing blood sugar levels. 

On the Q&A podcast, Dr. Meschia discusses stroke prevention, the warning signs of stroke and the latest in stroke treatments.