When it comes to our hearts, what we 'feel' isn't always the best indicator of what's going on below the surface.

For instance, when we're given a sudden fright, it can sometimes feel as though our pounding heart is going to leap out of your chest - but it won't! On the other hand, symptoms that seem quite mild might actually be a sign of an arrhythmia (abnormal heart rhythm) that needs to be checked by the experts.

And that's why, if you have any concerns about your heart or pulse, it's always best to talk them through with your doctor. If they too are concerned, usually a first step is to refer you for an electrocardiogram (ECG); machines can give a far more thorough picture of what's going on.

In the meantime, Trudie Lobban, founder and CEO of Arrhythmia Alliance (www.heartrhythmcharity.org.uk), and Christopher Allen, senior cardiac nurse at British Heart Foundation (www.bhf.org.uk), answer some common queries...

:: Sometimes, particularly when I lie down at night, I get palpitations for no reason and it's worrying me.

"Palpitations are a feeling that your heart seems to be beating faster than normal, and some people describe it as skipping a beat or fluttering. Lots of people say they are only really aware of the symptoms when lying in bed and, in most cases, although frightening, palpitations are not dangerous and may be due to anxiety," says Lobban. "However, it's still important to have the possibility of any underlying heart condition ruled out, so you should make an appointment to see your GP and request an ECG for this purpose."

Allen adds: "Many factors, including stress and anxiety, can trigger palpitations. Not smoking, and cutting down on alcohol and caffeine, can help to reduce them."

:: My teenage daughter is suffering with panic attacks and says she's terrified her heart is going to stop.

"Panic attacks can be very distressing, and even lead some people to attend A&E, feeling as though they're having a heart attack, especially the first time it happens," says Allen. "It's important to try and get to the root cause of these attacks to try and prevent them occurring more frequently, sometimes with medications and counselling support. Also, be reassured that a panic attack will not cause a cardiac arrest in an otherwise healthy person."

Lobban adds that she can "totally understand your daughter's concern".

"The physical symptoms are frightening and often accompanied by feelings of sheer terror and bewilderment," she explains, "but you must reassure her that a racing heartbeat and shortness of breath will not cause a heart attack.

"Panic attacks can be a combination of physical and psychological reasons. The saying 'it is good to talk' can be very apt and talking therapy, in the form of cognitive behaviour therapy [CBT], has proven long-term benefits for a panic disorder."

:: I've really got into the gym and fitness lately, but I've noticed that when I'm really pushing myself, my heart beat becomes a little irregular, should I get it checked?

"Exercising in the gym will obviously increase your adrenaline. These palpitations associated with exercise are not usually dangerous unless, of course, an underlying heart condition exists," says Lobban. "The only way to be reassured, so you can happily continue your fitness regime, is to ask your doctor for an ECG to help rule out any problem."

Allen adds: "When you physically exert yourself, it's normal for your heart to beat much faster than at rest - but it should always be regular. You should definitely make an appointment to see your GP; they can check your pulse and arrange for you to have an electrocardiogram (ECG) to check the electrical activity in your heart. They might also want you to wear a small, portable ECG monitor for 24hrs or more, to see if your heart rhythm changes at all through the day."

:: My uncle died from a sudden cardiac arrest. I've read this can be a faulty heart rhythm that may run in families, should I be concerned and can I get tested?

"Sudden Cardiac Arrest [SCA] is unpredictable and can happen to anyone, anytime, anywhere," says Lobban. "One of the risk factors is a family history and in your family, sadly, it was your uncle. There are inherited conditions that can cause SCA, which is why it is essential that any close or relatively close family members should always be offered an ECG, from which an electrophysiologist would be able to detect any underlying characteristics that could indicate a person may be at risk of cardiac arrest."

Allen agrees that testing is important: "In any family where someone has died following a sudden cardiac arrest, usually the coroner will recommend all first-degree relatives are referred for genetic testing - this means the parents, siblings and children of that person. Before you are offered genetic testing, your parent [the sibling of your uncle] will need to be tested first. If their result is positive, you will then be offered testing.

"However, if their result is negative, you won't need testing because they can't pass down a faulty gene that they don't have," he adds. "Contrary to popular belief, faulty genes do not 'skip generations'."