Visit your most convenient DMV office (see Resources) and request a DOT physical form. If you have recently applied for a CDL, you are likely to have been given this form during that process. You can also visit your state's department of transportation web site and print off a medical report form at home.
Book an appointment with your physician and ask her to complete the DOT physical form (see Resources). Your doctor will ask you a series of questions and perform a basic physical; she may also take and test a blood sample -- this is used for routine health and drug checks. Complete all stages of testing, which includes vision and hearing tests, blood pressure check and a health history questionnaire.
Follow your physician's advice in order to qualify for your medical examiner's certificate if you fail the DOT physical test the first time around. Make the recommended adjustments to your lifestyle or complete a course of medication so that you can, in the future, reapply for a medical card and qualify for your CDL.
Return to your DMV office and submit your completed and endorsed DOT physical form. You will receive a medical examiner's certificate, colloquially known as the DOT medical card, which proves you are fit and healthy to operate a commercial motor vehicle (CMV).