Delirium is a state of decreased cognitive function. It is a complex symptom in which a person becomes confused and has significant changes in behavior and mental state. Signs of delirium include problems with attention, awareness, emotions, and muscle control. Many medical conditions can cause delirium. People with delirium often recover completely after treatment for the condition that caused it. However, recovery does not always occur. Signs of delirium usually come and go during the day. There may be periods when a person shows no signs of delirium. Signs of delirium appear quickly. They may develop over hours or days. The main sign of delirium is a decreased ability to understand and perceive situations and surroundings. A person with delirium may have difficulty staying focused on a topic. Symptoms of delirium: Delirium occurs when the brain is no longer able to function properly. This may be due to infection, toxins, severe pain, or substance abuse. Doctors know of factors that can increase the risk of developing delirium. These factors are called "risk factors." Older people, those in hospitals or long-term care facilities, are at higher risk for delirium. Malnutrition is another risk factor for delirium. A person is also more likely to develop delirium if they are dehydrated. People with long-term or severe illnesses, as well as those with life-threatening illnesses, are also more likely to develop delirium. HIV and AIDS are examples of these diseases. Other risk factors include: Treatment for delirium depends on several things. To do this, the doctor must determine what caused the delirium. For example, stopping certain medications can treat the condition and make the delirium symptoms go away. It may also take a long time for the person to recover, either at home or in care facilities. Sometimes delirium does not last long, sometimes it goes away after a few hours, and sometimes it lasts longer, up to weeks, months, or years. Supportive care, such as relaxation and rest, can help with treatment and start the recovery process. Examples of permanent care include: The injured person’s healthy mental state must also be maintained, and this can be done through: