This is an awareness of difficult and distressing breathing at rest or with
minimal physical activity. There are several possible underlying causes. The
characteristics of the current or previous episodes and a family history of
similar occurrences are all helpful clues, alongside a thorough physical
examination, in determining the cause in most cases.
CAUSES
· Cardiac disease
· Respiratory disease
· Anaemia
· Metabolic acidosis (e.g. in renal failure)
· Anxiety
Acute onset
· Asthma
· Pneumonia
· Pulmonary oedema
· Pulmonary embolism
· Pneumothorax
· Foreign body aspiration
Nocturnal episodes
· Left ventricular failure
· Asthma
DISORDERS OF THE CARDIOVASCULAR SYSTEM
· During exertion
· Respiratory failure
· Heart failure
· Chronic anaemia
· Congenital heart disease
After exertion
· Heart failure
· Asthma
On lying flat on a bed (Orthopnoea)
· Heart failure
Slowly progressive in severity
· Chronic respiratory disorders (chronic bronchitis, emphysema)
Associated with wheezing
· Asthma
· Heart failure
Associated with wheezing during the working week
· Exposure to occupational allergen
Associated with deep respirations of acute onset
· Metabolic acidosis e.g. diabetic ketoacidosis or uraemia.
Associated with fever
· Respiratory (pneumonia, lung abscess, empyema)
· Cardiac (Endocarditis, Pulmonary embolism)
Associated with cough
· Respiratory (pneumonia, lung abscess, empyema)
Associated with sputum production or pleurisy
· Respiratory (pneumonia)
SYMPTOMS
See appropriate section for symptoms of the following conditions
which may cause dyspnoea.
SIGNS
Cardiac
· Frothy blood-stained sputum
· Elevated blood pressure
· Orthopnoea
· Cardiomegaly
· Murmur
· Rhonchi
DISORDERS OF THE CARDIOVASCULAR SYSTEM
Respiratory
· Rhonchi
· Tachypnoea
· Fever
· Dullness on chest percussion
· Bronchial breath sounds
· Crepitations
Foreign body aspiration
· Wheezes
· Crepitations
INVESTIGATIONS
· FBC
· BUE and creatinine
· ECG
· Chest X-ray
· Other investigations depending on suspected cause (See appropriate
sections)
TREATMENT
Treatment is based on the underlying condition (See appropriate sections).
REFER
Refer to a hospital if cause cannot be identified after ensuring that the
airway is clear and circulation is satisfactory.
