Foam is an efficient thermal insulator, so the temperature of the oil can become difficult to control. The presence of air bubbles in the fluid can lead to excessive oxidation, cavitation, the reduction of lubricating properties of the oil and hydraulic system failure. Causes The causes of foaming are many. The most common include: Water contamination
Psychosis refers to an abnormal condition of the mind described as involving a loss of contact with reality. People with psychosis are described as psychotic. People experiencing psychosis may exhibit some personality changes and thought disorder.
Neurosis is a class of functional mental disorders involving chronic distress but neither delusions nor hallucinations. The term is no longer used by the professional psychiatric community in the United States, having been eliminated from the Diagnostic and Statistical Manual of Mental Disorders in 1980 with the publication of DSM III.