Why might a pilot need to undergo additional medical testing?

A pilot may need to undergo additional medical testing primarily due to a history of significant medical conditions. This is important because certain health issues can affect a pilot's ability to safely operate an aircraft. The Federal Aviation Administration (FAA) mandates that pilots must meet specific medical standards to ensure they do not pose a risk to themselves or others in the course of flying.

If a pilot has a history of conditions such as cardiovascular issues, neurological disorders, or any other significant ailments that could impair their performance or decision-making abilities, further evaluation and testing are necessary. This process helps the medical examiner assess whether the pilot can safely continue flying and helps to maintain high safety standards in aviation.

The other options would not compel a pilot to undergo additional medical testing based on the same guided safety practices and regulations governing aviation.