Which prefix indicates a condition that is bad, painful, or difficult?

The prefix that indicates a condition that is bad, painful, or difficult is "Dys-." This prefix is derived from the Greek word "dys," which means "bad" or "difficult." It is often used in medical terminology to describe various conditions or symptoms that involve abnormal, impaired, or painful states. For example, "dysfunction" refers to abnormal or impaired functioning of an organ or system, while "dysphagia" refers to difficulty swallowing.

In contrast, the other prefixes have different meanings. "Macro-" refers to something large or oversized, such as in "macrosomia," which describes a newborn with a birth weight larger than normal. "Melan/o-" pertains to the color black or dark, often used in terms like "melanoma," a type of skin cancer involving melanocytes. "Micro-" indicates something small, evident in terms like "microorganism," which denotes tiny living organisms that can only be seen with a microscope. These prefixes do not convey the meaning of bad, painful, or difficult conditions, making "Dys-" the correct choice.