Delirium is a mental disturbance that causes confusion when an individual becomes medically unwell. This condition may develop quite rapidly, sometimes within a few hours. It can be caused by certain medications, chronic mental illness and infection or as the result of alcohol withdrawal. Generally, individuals with delirium tend to become well when the cause is resolved. Delirium appears to be common among the elderly, terminally ill patients, those affected with head trauma and memory problems. There are three types of delirium; hyperactive, hypoactive and mixed delirium. Hyperactive delirium includes mood swings, restlessness or hallucinations. Individuals with hypoactive delirium experience abnormal drowsiness and tend to be inactive. Mixed delirium can include both hyperactive and hypoactive when individuals can switch between one and the other.


Delirium develops when the signalling system in the brain becomes affected. Various triggering factors can contribute to the malfunction in the brain. In some cases, more than one single cause is associated with developing this condition and in other cases, the cause can remain unknown. The most common cause of developing delirium can include urine infection, major surgery, kidney malfunction, side-effects of medications, high temperature particularly in children, exposure to the toxic substance, alcohol abuse, dehydration, severe lack of sleep, brain infection, terminal illness and being in an unfamiliar place. Certain drugs can also trigger delirium and this can include medications used for conditions such as asthma, parkinson’s disease, depression, mood disorders and allergy.


An individual suffering from delirium is able to change their mental states with fluctuations throughout the day. The symptoms of delirium include developing the inability of the person to remain focused, easy distraction, remaining withdrawn, unaware of the activities in their  surrounding, unable to converse clearly, agitation and mood swings that change from being anxious to frightened or irritability. Additional symptoms can include confusion, sleepiness, worry that others can harm them, seeing things and hearing voices.


Diagnosis of delirium is based on the identification of the underlying problem that causes this condition. This can include the evaluation of the individual’s medical history and various tests to determine the mental condition. Diagnosis can include neurological examination, cognitive and motor function tests. Mental status assessment can determine the individual’s state of confusion, memory and perception. To determine the cause of the underlying problem, additional tests can include chest x-ray, head CT scan, head MRI scan, cerebrospinal fluid analysis, blood and urine tests.


The treatment is usually focused on identifying the underlying problem and treating that condition. Depending on the case, treatment of the infection or by stopping the use of particular medication can reverse the symptoms of delirium. It is also essential to create a safe and serene environment for the individual to calm the brain. Although full recovery is possible, it can take several weeks for the affected individual to resume normal mental function.