Shortness of Breath and the Heart: What to Know

Shortness of breath can come from the heart or lungs, so new, severe, or worsening symptoms need prompt medical assessment. Heart-related breathlessness may happen when the heart cannot move blood efficiently, causing pressure to build in the lungs. It can appear during activity, when lying flat, or with swelling around the ankles. Other explanations include asthma, a chest infection, anaemia, or a serious allergic reaction. The symptom alone cannot identify its cause.

Heart-related breathlessness can occur with chest pressure, unusual tiredness, dizziness, a racing or irregular heartbeat, or difficulty breathing when lying down. Angina may cause discomfort or tightness during exertion, while an irregular rhythm such as atrial fibrillation can reduce how effectively the heart pumps. Breathlessness can also accompany conditions such as Angina, Atrial Fibrillation, or Anaemia. A wheeze, cough, fever, phlegm, or a history of smoking can point towards a lung or airway cause, including Asthma or COPD. These patterns guide assessment but do not replace an examination.

Stop strenuous activity and sit upright if breathing feels difficult. Note when the symptom began, whether it follows exertion or occurs at rest, and whether lying down makes it worse. Record associated chest discomfort, palpitations, cough, fever, swelling, or faintness, along with any new medicine or recent illness. Arrange a clinical review for unexplained breathlessness, especially if it keeps returning or limits ordinary activity. A clinician may check your heart rhythm, oxygen level, chest, blood pressure, and blood tests, then decide whether further tests are needed.

Seek emergency help immediately for severe or rapidly worsening breathlessness, breathing difficulty with chest pressure or pain, fainting, new confusion, blue or grey lips, or inability to speak in full sentences. Treat sudden breathlessness with facial or throat swelling, hives, or wheezing as a possible Anaphylaxis emergency. Sudden breathlessness with coughing blood, marked weakness, or a very fast or irregular heartbeat also needs urgent assessment. Do not drive yourself if you feel faint, confused, or severely short of breath.

Ask what findings make a heart cause more or less likely, whether your medicines could affect breathing or heart rhythm, and which symptoms should trigger emergency help. You can also ask whether you need an electrocardiogram, blood tests, or breathing tests, and what level of activity is reasonable while the cause is being assessed.