And what can cause heart attacks

Yes, you can have a heart attack at any age. There are numerous causes of heart attacks.

It is a very complex topic, far wider than what can be discussed here. Suggest you Google the topic and subtopic, there are thousands of websites the view. Basically you can have a heart attack at any age and the reasons could be congenital, diet related, etc. etc.

May I ask why you are asking? Do you think you are at risk for one?

I've had two realitives die of heart attacks before their early 30's. Without known heart defects as an example...and its NOT on the lower end by far. Just watch the news...some high school athlete dies every year someplace.

I have a classmate have one at 20. It can and does happen at any age. The issues that cause heart failure is many.

Are you having problems?