Most often these defects are asymptomatic through out the life time. They can lead a normal life without any difficulty upto the age of 30 years. Rarely they can cause breathlessness, palpitation, giddiness and so on.

Hi welcome to healthcare magic,
ASD i.e Atrial septal Defect is usually asymptomatic if small .
If moderate will present with symptoms later in life usually by 40-50 years age.
Is severe he would have symptoms by now.
So size of ASD matters a lot and not everybody follow this rule, exceptions exist.
The best thing would be take a pedicatric cardiologist opinion , see if he advices surgery ( the surgery is not a open heart surgery , its a simple one which they do it by passing a wire through a vein , with good success rate ) and if not just follow up with him yearly or every 6 months to see if the size is increasing.
No special precations are needed , except for get him adequately treated if he gets any throat infections....
Hope this was informative .

Atrial defects does close spontaneously after some time. So you should not worry upon that.

Hi.. The treatment for the atrial septal defect is only done when the defect is large and when there are symptoms.

The treatment may include surgical closure if the problem is severe or just supportive treatment for prevention of breathlessness.

Hence when your doctor has mentioned that it is not a worry now, you can believe in him. Just have regular follow up with the doctor who will be monitoring his symptoms and condition.

Avoid undue exertions, that should do in keeping in the normal state...