Julia Kagan is a financial/consumer journalist and former senior editor, personal finance, of Investopedia. Lea Uradu, J.D., is a Maryland state registered tax preparer, state-certified notary public, ...

An intelligence quotient or IQ is a score derived from a set of standardized tests developed to measure a person's cognitive abilities ("intelligence") in relation to their age group. An IQ test does ...

What is empty sella syndrome? Empty sella syndrome (ESS) is a rare disorder that affects a structure in the skull called the sella turcica. This is a bony structure at the base of the brain. It is ...