Further investigations

Some tests are available in the GP surgery, others need to be done as a hospital out patient.


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  • Sputum culture. If the patient has a cough with sputum, this is sent for testing to indicate bacterial infection. The colour of sputum is important. Always send the sputum sample for testing if the patient has haemoptysis (blood in sputum).
  • Blood tests. Haemoglobin and Full Blood Count may be useful as a base line. C-Reactive Protein test is a blood test marker for inflammation. Levels rise in response to an inflammation somewhere in the body so a blood test is useful if there is a suspected diagnosis of infection, fibrosis or cancer.
  • Chest X-ray. Should be done early for all patients. It is often diagnostic. It can show areas of the lungs which may have infection, fluid or other abnormality. It can also exclude other non respiratory diagnoses which cause breathlessness.
  • Spirometry. This is a more detailed test of the air flow in and out of the lungs and the capacity of the lungs. It can be done in some GP surgeries or hospital out patient clinic. In hospital it is often combined with other lung function tests.
  • Referral for specialist assessment. Respiratory conditions such as asthma and COPD can be diagnosed and treated in the community. Other respiratory conditions often need CT scans which are done in hospital by hospital respiratory specialists. 
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