DefinitionIrritability is an excessive response to stimuli.Alternative NamesInconsolabilityConsiderationsThe term "irritability" is used for infants and young children who, when ill, are especially fussy, whiny, and fretful, despite attempts at comforting and soothing them.Parents are usually very aware of their child's normal behavior and may pick up early changes that the health care provider wouldn't notice. This can help diagnose illness early.Common CausesIrritability can be a very early sign of serious problems. Although irritability is not a symptom of any specific illness, it should arouse suspicion in the parent that something might be wrong with the child, even though there may not yet be other symptoms.Causes of irritability include:Alcohol or drug withdrawal stateAutism spectru