Which prefix signifies that something is difficult or painful?

The prefix that signifies something is difficult or painful is "dys-." This prefix is derived from Greek and is commonly used in medical terminology to describe conditions that are abnormal, difficult, or impaired. For example, "dysfunction" refers to an abnormal functioning of a part of the body, and "dysuria" indicates painful urination.

Understanding this prefix is essential for recognizing medical terms and their meanings, as it helps convey the nature of symptoms or conditions that may involve difficulty or pain. In contrast, the other prefixes have different implications; "hyper-" refers to excessive or above normal, "inter-" signifies between or among, and "post-" indicates after or behind. Each of these prefixes has distinct uses in medical terminology that do not relate to difficulty or pain.