How do you know you have mental illness when you apply for a health certificate?

When you apply for a health certificate, you usually don't know whether the applicant has mental illness directly through the ID card information. The examination items of health certificate are basic examination items, such as blood routine, liver and kidney function, abdominal B-ultrasound, electrocardiogram and chest X-ray examination, and other examination items are not done. If there are special circumstances, the doctor can examine or ask the applicant more carefully to ensure the health and safety of the applicant.