Why do young people suddenly drop dead from cardiac arrest?

I sometimes read about young people (often, but not always, athletes) who are in their 20's and just drop dead from a heart attack. They aren't old enough to have clogged arteries (I guess). Is it some underlying heart trouble they are born with but hasn't been detected? Pushed themselves too far physically? Interested.

Cardiac arrest in young people can be caused by drug use certain steroids, cocaine and its derivatives, an enlarged heart, high blood pressure, anorexia, heart arrhythmia, congenital heart defects, extreme obesity and clotting disorders can also be the cause.

You can actually have clogged arteries at any age but it is more likely a congenital heart problem that may have been undetected. Usually in sports figures there is an underlying heart problem which is exacerbated by physicality of sports.

usually a heart defect, some of us have them and will never know because to us it`s normal, we had 2 classmates that died because of a heart defect, many things can affect your heart, stress for one, anyone who`s ever been to high school knows that some days can be horribly stressful, diet is another thing that can affect your heart and some heart defects only show up when the heart is stressed, so it won`t show up in a regular doctors visit.

Some have a congenital, often inherited, condition called a cardiomyopathy, more specifically idiopathic hypertrophic subaortic stenosis. The heart muscle can enlarge to the point of obstructing blood flowing into the aorta, causing sudden death.

Others may have an arrhythmia, an abnormal conduction pathway that regulates the heartbeat in an efficient way. If the heart muscle contracts irregularly, it cannot pump blood efficiently.

Still others may have been born with a single coronary artery, and suffer a heart attack when under physical stress.

There are uncommon inherited dislipidemias where elevated cholesterol and other lipids cause rapid buildup of plaque in the coronary vessels.

Although not caused by a heart attack, some athletes die as a result of Marfan syndrome which is associated with acute rupture of the aorta, the main vessel coming from the heart.

On the preparticipation sports exam in most states, there is a question such as, "Has anyone in your family died during sports participation or strenuous exercise?" It is a very important question, since most of the above conditions have strong hereditary components.

Usually an undiagnosed cardiac condition such as a faulty valve, hole in the heart, stenosis(narrow vessel) etc...

Though it remains unclear with doctors, as to why teens often die abruptly, while playing sports, I can tell you the real truth.

It can be taking drugs, such as speed (meth).
The teen probably took the drug before playing sports, and when someone dies, basically everything inside has failed to to continue to work, so digestive system acid instantly diminishes the drug, such as meth, leaving doctors clueless as to what caused the death. They will then say it was due to a birth defect or respiratory failure.

It can also be a number of heart conditions. There is this disease which some people may have but not know about, until they have an attack or don't live to tell about it.

It is known as PATENT DUCTUS ARTERIOSUS, when the ductus fails to close after birth. The death can cause congestive heart failure, which is sudden death.

The athlete probably had an addiction with drugs, had stayed away from the drug, but had been overworking his heart in the past, from sleep deprivation and muscle, oxygen exertion.

Not all heart attacks are caused by a clot.