Hallucinations

What are hallucinations?

A hallucination is when you sense things that are not real, even though they seem very real to you. Hallucinations may involve any of the senses, such as:

• hearing voices when no one is speaking
• seeing things that are not there
• feeling things crawling on you that are not there
• smelling scents that are not there
• tasting flavors that are not there

Smell and taste hallucinations are rare.

Hallucinations are not the same as illusions. Illusions are when you see or hear something and think it is something else. An example is a person who sees a lamp out of the corner of their eye and thinks it is a person, or hears the wind and thinks it is voices. A person having hallucinations may be completely out of touch with reality.

How do they occur?

Some causes of hallucinations include:

• fever, especially in children and older adults
• serious illness such as liver failure, kidney failure, or brain cancer
• mental disorders such as schizophrenia or bipolar disorder
• brain damage
• dehydration
• side effects of medicine
• severe lack of sleep
• stress
• drugs such as LSD, poisonous mushrooms, or PCP
• heavy alcohol use or withdrawal

Some people have hallucinations right before they get a migraine or have a seizure.

What are the symptoms?

There are different kinds of hallucinations:

• Visual hallucinations may be unformed shapes or colors, or things such as animals or people. The person sees things that no one else can see. Drugs like LSD may cause visual hallucinations. Blind people sometimes have hallucinations of seeing things. People with dementia also may have this kind of hallucination.
• Auditory hallucinations occur when a person hears voices or sounds that no one else hears. People with schizophrenia often have this type of hallucination. Deaf people may have hearing hallucinations. This type also occurs from using certain drugs.
• A tactile hallucination is the feeling of something crawling on the skin. These kind of hallucinations most often occur when drugs or alcohol are used or during withdrawal.

How are they diagnosed?

Your healthcare provider will ask about symptoms and examine you. He or she will make sure that symptoms are not caused by a medical problem or by drugs such as LSD or cocaine.

If no medical cause can be found, you may be referred to a mental health professional for further testing.

How are they treated?

Treatment depends on the cause. If hallucinations are rare, or if they do not interfere with your life, no treatment may be needed.

Hallucinations caused by mental health disorders, such as schizophrenia can generally be controlled with medicine. If hallucinations are caused by medicine, changing the dose of medicines may correct the problem.

Hallucinations can be scary for the person having them and for anyone around them. When someone is having hallucinations, it is important to keep calm. If hallucinations are new, intense, or involve hurting self or others, get medical help right away.