Palpitations (the sensation of your heart beating) are common. Most cases are harmless. They usually only last for a short time and can be accompanied by other symptoms such as breathlessness, dizziness, chest tightness and a feeling of anxiety. Palpitations that are severe or don't settle quickly may need urgent medical attention. The most common causes are mentioned below.

What are palpitations?

Palpitations are rapid, thumping or fluttering feelings that people experience in the left-hand side of the chest, usually above the nipple. Some people say their heart feels like its racing; others say their chest hurts, thumps or flutters. Usually this sensation is caused by a heart rate that is faster than usual for your age, gender and level of fitness. Occasionally, the feeling is due to an irregular heart rate.

What is the heart?

The heart is a muscle that pumps blood round the body. It has two upper chambers - the right atrium (RA) and the left atrium (LA) - and two lower chambers - the right ventricle (RV) and the left ventricle (LV).

The pumping movements of the upper and lower chambers of the heart are co-ordinated to ensure constant circulation of the blood through our bodies. When we need more oxygen to reach our cells - eg, when exercising - the heart beats faster to pump more blood to the lungs and cells.

An electrical impulse is generated in the RA. It travels across to the LA and down to the RV and LV. This electrical impulse stimulates the chambers of the heart to contract, which propels blood out of the chamber. 

What types of palpitations are there?

Palpitations can be caused by an unusually rapid but regular heart rate, extra beats or an abnormal heart rhythm.

The heart usually beats at around 70 beats per minute (bpm). The normal range for an adult can be anything from 40-100 bpm. Your normal resting rate depends on your age and level of fitness (generally speaking, the fitter you are, the slower your pulse, and heart rate increases a little with age). Your normal heart rate may increase due to exercise, anxiety, caffeine, other stimulant drugs or an overactive thyroid gland.

Extra beats are usually harmless and occur because all heart muscle cells can generate an electrical signal that can spread outside the normal pathway mentioned above. They feel like a missed beat or thump in the heart and are usually felt when resting.

An abnormal heart rhythm can cause palpitations. Your pulse will feel irregular because the heart will be beating in an unco-ordinated way. An abnormal heart rhythm can result from abnormal electrical activity in the atria or ventricles. Those originating from the ventricle are less common and potentially more dangerous than atrial ones.

What problems can cause palpitations?

This list does not include all the possible causes of palpitations but lists some of the more common causes including:

Sinus tachycardia (fast, regular heartbeat)

The most common reasons for the heart rate to speed up are drugs. These include caffeine, alcohol, and recreational drugs like cocaine; over-the-counter cough and cold medication, and some prescribed medicines - eg, salbutamol for asthma.

Anxiety and an overactive thyroid gland can also cause the heart to speed up which may result in palpitations.

A serious underlying abnormality of the heart is a rare cause of sinus tachycardia. Serious heart problems are more likely to causes prolonged runs of palpitations and associated problems such as breathlessness.

You are likely to be asked too about your intake of the substances, mentioned above, and the circumstances in which the palpitations occur. Your doctor will take your pulse and blood pressure, listen to your heart and order further tests as appropriate. The treatment will depend on the likely underlying cause.

Extra systoles (ectopic or missed beats)

Theses extra beats occur when heart cells fire off an electrical impulse outside of the normal, coordinated impulses which make the heart contract. After an extra beat, the heart rests or a little longer than usual and this feels like a missed beat. The extra beats are harmless and tend to occur at rest and disappear during exercise. The diagnosis is made by seeing the extra beats on an electrocardiogram (ECG). No specific treatment is needed.

Atrial fibrillation (AF)

AF is the most common arrhythmia and causes an irregular, usually rapid, heartbeat. The upper chambers of the heart (atria) beat in an unco-ordinated way. It becomes more common as you get older and if you have high blood pressure or underlying heart disease. Excess alcohol and an overactive thyroid (hyperthyroidism) may also trigger AF. The diagnosis is made by the doctor feeling an irregular pulse and is confirmed on an ECG. Treatment can include medicines to slow down the heart rate (eg, bisoprolol), medicines to restore normal rhythm (eg, flecainide) and medicines to thin the blood and prevent a stroke (eg, warfarin). Other types of treatment include cardioversion (electric shock treatment to restore normal heart rhythm), catheter ablation (destruction of the area of the heart causing the abnormal rhythm) and pacemaker insertion (to override the heart's natural rhythm).

Supraventricular tachycardia (SVT)

This is another cause of palpitations. The heart starts racing extremely fast then stops or slows suddenly. SVTs happen when abnormal electrical impulses start in the atria and override the normal co-ordinated electrical system of the heart. There is often no underlying reason. Some people find their SVTs are triggered by exercise, getting upset, coffee or alcohol. They often happen for the first time in young people. Most cases are harmless and don't require treatment. If troublesome, treatment with beta-blocker medication (eg, bisoprolol) which slows the heart down or catheter ablation (see under 'Atrial fibrillation (AF)', above) can be effective.

Ventricular arrhythmias

These are much less common, and potentially more dangerous, than atrial arrhythmias such as AF and SVT. Diagnosis is made by an ECG and referral to a cardiologist (heart specialist) for expert advice will be necessary.

What investigations might be advised?

Most people with palpitations will be offered blood tests to check for anaemia and an overactive thyroid. You may be asked to have an ECG which records the electrical activity of your heart to check for underlying or previous heart disease and whether the heart rate is regular. A 24-hour ECG records the electrical activity of the heart over a 24-hour period. You may be asked to try to have the ECG while experiencing palpitations. Further investigations of the heart may be necessary.

What treatments may be offered?

Treatment will depend on the likely cause of your palpitations. You may be asked to cut down your caffeine intake or keep a diary of the circumstances in which the palpitations happen. Most cases will be managed by your GP but you may be referred for further investigation and treatment at a hospital.

What should you do next?

If you have palpitations that do not go away quickly (within a few minutes), or have any chest pain, severe breathlessness or dizziness, you should call an ambulance. If the palpitations are less severe but are persistent or recurring, you should see your GP.

If you have an episode of palpitations it can be useful to check your pulse. In particular it may be useful for your doctor to know how fast your pulse was during the episode. That is, how many beats per minute. Also, if your pulse felt regular or irregular. This information an help identify the cause of the palpitations. Your practice nurse can show you how to take your own pulse if you do not know how.