Lung ultrasound has been used to help diagnose COVID-19 as an alternative to CT scanning and chest X-ray. CT scanning is onerous and there are difficulties taking critically unwell patients there as well as decontamination issues.

Chest X-ray misses up to 40% of COVID diagnoses. Although lung ultrasound can diagnose, the investigators do not know how long these lung ultrasound changes last. The investigators would like to follow up patients to characterise the pattern of changes and how long they last. This is particularly important given a potential second surge of COVID-19 is looming and the investigators would like to know if lung ultrasound changes are new or old in patients presenting during this second wave and in the future.

Ultrasound has been invaluable during this pandemic to diagnose COVID-19. The investigators have used it alongside CT scanning to rationalise the number of CT scans especially when patients are unstable. The investigators do not know how long these changes last on lung ultrasound after discharge and the investigators wish to study this.

This is because patients will start presenting shortly who have a history of COVID-19 with acute medical problems and if the investigators are to use lung ultrasound again the investigators would like to know whether the changes the investigators see are new or old.

This is vitally important before a second surge and especially so before winter. This may also facilitate triage of patients from the front door in the Emergency department to different areas (such as COVID-19 zones or clean areas).

Inclusion Criteria:

• 18 years old or older
• Confirmed COVID-19 positive with changes on CXR or CT scan
• Having had an initial lung ultrasound in the Emergency department when they were first admitted into the hospital.

Exclusion Criteria:

• Pre-existing lung disease
• Heart failure
• Under 18 years old.

Adults with a confirmed COVID-19 viral infection.