These include epilepsy, diabetes, and recent heart ailments. When you are about ready to solo, your flight instructor will send you to a local FAA office where you can be issued a student pilot certificate. This is only valid when endorsed by the instructor and must be revalidated every 90 days for continued solo flight privileges. In addition to the flight test, each applicant must pass a knowledge test. The knowledge test must be successfully passed before the flight test may be taken.
Some people prefer to take the knowledge test before they begin flight training.
Many people study for and take the knowledge test while taking flight lessons, and find that the theory and practical work complement each other, thus making both types of training easier. It's really a matter of personal preference as to which approach to take. There are three commonly used methods of preparing for the knowledge test. One is to take a regular course given by flight schools and local colleges. These typically meet once to several times per week and take about a semester to complete.