It is usually done at regular intervals as an annual medical check up, or once in two to three years, depending on one's risk factors and age. Health screening may range from blood tests to cancer screening and tumour markers tests, to other diagnostics scans such as Ultrasound scans, Mammogram or Chest X-Ray. You may also opt for these tests as part of your routine health screening if necessary. Early detection of abnormalities or lifestyle diseases can lead to earlier intervention which leads to better outcomes.