How do you know if you have a heart defect?

My friend says they have a heart defect. How do you find out if you do? Do yoru parents find out at your birth? Does a doctor listen to your heart and realise? Would you have a stroke or heart attack or something and then find out?

Oh, Im not worried about myself... although I did hear my heart squeaking on one quiet night! And Im not good enough friends with my friend to ask them something random like how they found out (as they told me months ago and I would feel a little like a stalker).

There are some very dramatic answers here.

Heart defects are not normally detected unless you have some reason to suspect one. Unexplained shortness of breath, chest pain/pressure, lightheadedness, etc.

In the event of long-term sympoms such as those above, you will have a 12-EKG done to look at the heart electronically, which will look at all aspects of your heart and provide a printout of 12 different views. You may be scheduled for an echocardiogram to look at the heart visually.

Most heart defects are benign -- murmurs, etc. They are simply identified and no action is taken.

well you caouldalways ask your parents about your family history or simply go to the doctor so they can run a poopload of tests to determine so...I found out I have slight heart murmur which doesnt really affect me so I guess you could consider that a defect..so if you had a serious one you would probably know about it already..

Either it shows up on tests at the doctor or you will have shortness of breath or fatigue at times but not at other times.
Sometimes it is the rhythm of the heart that is interupted that makes a person feel dizzy or weak.
A stroke can come from a blood clot or leaky valve.
Heart attack , you will have the worst pain ever in your left arm.

Many heart ailments cause no problems but show up on testing.

Stop worrying about your friend(s) heart issue and worry about your terrible spelling and grammar.

Doctor could

listen to your heart, check for abnormal beat or murmur
take an EKG to check the rhythm
Do an ultrasound to check size
Xrays
Bloodwork.

Maybe it wasn't your heart which squeaked, but some organ in your digestive system: i.e. the esophagus.

But maybe it's an early sign of heart murmur.
Many people live with a heart defect and do not even know it until they actually have a serious attack where they can't breathe, feel as if they're gonna drop dead, and lose control and consciousness.

If you think you should be concerned, ask your parents. They shouldn't be hiding anything, especially if it's something about your health.

Doctors usually listen to your heart when you go into a regular visit, because it is required by law. Since the heart is our life, they need to check for heart abnormalities and they are detected by listening to the heartbeats. That's what then leads doctors to send you for a heart scan.

Go to the doctor and take your friend with you. You shouldn't feel like a stalker. There's a way for everything, and she will not consider you a stalker. Leave those silly thoughts out of your life.

You would have to be diagnosed ny a cardiologist (heart doctor) they can preform an eccocardiogram of the heart, This is like an ultrasound. It looks inside the body and see the heart and detect an abnormality. This procedure is non surgical. However, it is still costly to have this done.
Depending on how severe a heart defect is; the doctors would decide what route to take