Environmental factors and genetics are two components that are associated with alcoholism, with about half the risk attributed to each.[3] A person with a parent or sibling with alcoholism is three to four times more likely to become an alcoholic themselves.[3] Environmental factors include social, cultural and behavioral influences.[14] High stress levels and anxiety, as well as alcohol's inexpensive cost and easy accessibility, increase the risk.[3][5] People may continue to drink partly to prevent or improve symptoms of withdrawal.[3] After a person stops drinking alcohol, they may experience a low level of withdrawal lasting for months.[3] Medically, alcoholism is considered both a physical and mental illness.[15][16] Questionnaires and certain blood tests may both detect people with possible alcoholism.[3] Further information is then collected to confirm the diagnosis.[3]