How tragic Indiana mom suffered one in 50,000 freak injury that can be caused by something as innocuous as COUGHING too hard or airplane turbulence

An Indiana mother who mysteriously died on her flight home from the Dominican Republic suffered a carotid artery tear, her family has revealed.

Stefanie Smith, 41, was killed in a 'truly a tragic medical event', her brother Chris Volz said, adding that the autopsy results did not suggest any foul play.

The injury occurs when an artery in the side of the neck tears and stops blood from reaching the brain - causing neurons to stop working and die.

The condition is rare, occurring in only one in 50,000 people, and can be caused by something as innocuous as forcefully coughing, blowing your nose, straining your neck, bad posture and airplane turbulence.

But most are caused by a traumatic injury like high-speed car or sporting accidents, which physically rip the arteries.

Stefanie Smith, 41, was just minutes into the American Airlines flight home from the Dominican Republic when she became fatally ill from an unknown cause on February 28 

Smith is pictured with her two children. The late mom's cause of death has now been revealed by her brother 

The tear allows blood to get in between the layers of the artery wall and separate them. This causes the artery wall to bulge, which can slow or stop blood flow to the brain. This can lead to a transient ischemic attack (TIA) or stroke

In many cases, carotid dissection can happen suddenly without a known cause, called spontaneous carotid artery dissection.

The tear allows blood to get in between the layers of the artery wall and separate them. This causes the artery wall to bulge, which can slow or stop blood flow.

It can also cause issues by pressing on nearby structures such as nerves.

The tear may prompt the body's clotting system. A clot may block blood flow at the site of the tear, or pieces of the clot may break off and block the flow in smaller branches of the artery.

Blocked or decreased blood flow can cause a stroke by starving the brain of blood and oxygen. A blood vessel that supplies the brain rupturing and bleeding can also lead to a stroke.

Carotid dissections can occur at any age, but is more common in people in their 40s and 50s and is a common cause of stroke in people under the age of 50, possibly because younger people perform more activities that could lead to a dissection.

It is slightly more common in men than in women.

Her brother Chris Volz, pictured with Stefanie Smith, has revealed that she died from a carotid artery dissection in her neck

Smith and her boyfriend had joined close friends Maria Yannotti, 36, and Clay Sharpe, 43, for a five-night stay at the all-inclusive Iberostar Grand Bavaro in Punta Cana, Dominican Republic.

But the romantic couples' getaway turned to tragedy minutes into her return flight when she started convulsing and was declared dead after the American Airlines plane diverted to the Turks and Caicos Islands.

READ MORE: Alabama boy becomes 'first in world' to be born to a mom with a transplanted WOMB 

His mother, Mallory, who prefers to keep her full name anonymous, was born without a uterus, making her infertile and fully diminishing her chances of conceiving a child naturally. 

A stroke, which can be caused by carotid dissections, prevents brain tissue from getting oxygen and nutrients, causing brain cells to die in minutes and ultimately death.

Seizures, where the body convulses, can occur after a stroke due to the electrical disturbance in the brain.

Research has suggested that prolonged, incorrect posture on a flight, such as leaning your head forward, can increase the chance of carotid dissection in people already at higher risk.

Aircraft turbulence may also raise the likelihood. 

Certain health conditions increase the risk of carotid dissections, including fibromuscular dysplasia, Marfan's syndrome, Loeys-Dietz syndrome, and Ehlers Danlos Vascular type IV.

But Smith's brother Volz previously told DailyMail.com he was not aware of his sister having any preexisting health conditions. 

Yannotti also claimed Smith was picture of health throughout their vacation, using the hotel gym and going for runs along the beach.

There have been reports linking carotid  dissection with weightlifting or intense exercises, but the specific relationship is not well understood.

One prospective study of 750 Canadian patients found that roughly 30 percent observed population who weightlifted more than 50 pounds experienced spontaneous carotid artery dissection.

Patients with carotid artery dissections are advised to avoid push-ups and sit-ups for eight to 12 weeks after the dissection, the American College of Cardiology said.

Cocaine use can also increase the likelihood of a carotid artery dissection.

Some people who have carotid dissection do not have any symptoms. With others, symptoms may occur suddenly or crop up over several days.

Symptoms can include headache, scalp pain, eye pain, neck pain, weakness on one side of the body and facial droop.

Sufferers may also experience problems with speech, trouble swallowing or an abnormal or lost sense of taste. 

When carotid artery dissection is diagnosed early, the prognosis is usually good, 

But it can be difficult to diagnose because symptoms vary significantly between patients.

Research suggested that with spontaneous dissection, less than five percent will die, with close to 75 percent of patients making a good recovery. 

With dissections caused by trauma, an estimated 37 percent – 58 percent of patients have lasting neurological problems with higher mortality rates compared to patients with spontaneous dissection.