Breathlessness is the sensation of difficulty with breathing. Sudden, unexpected difficulty with breathing is a serious medical problem and the most common reason why people ring 999.
It is normal to get out of breath when you have over-exerted yourself, but when breathlessness comes on suddenly and unexpectedly, it is usually a warning sign of a medical condition and you should seek immediate medical attention. Getting breathless with exertion is common but getting breathless with very minimal exertion, such as performing the activities of daily living can be a sign of heart disease and needs further assessment.
Breathlessness can be due to a number of causes such as lung or heart disease. From the point of view of the heart, breathlessness can be a symptom of heart failure where the heart pump is weakened and has difficulty pumping blood. There may be a reduction in the blood supply to the heart muscle which usually causes chest pain, but in some patients, particularly in patients with diabetes, breathlessness may be the only symptom. Breathlessness may also be a symptom of an abnormal heart rhythm of which the most common is atrial fibrillation.
Both lung and heart disease are common causes of breathlessness and should always be investigated. From the heart point of view, your Cardiologist will want to perform an ECG, some simple blood tests and an echocardiogram to find the cause. In many patients, further tests will be needed to delineate the underlying cause and this requires careful expert attention.