Hallucinations are sensory experiences that seem real but are created by your mind. They can affect all five senses. For example, you may hear a sound that no one else in the room can hear or see an unreal image.
These symptoms can be caused by mental illness, side effects of medications, or physical illness such as epilepsy or alcohol use disorder.
Depending on the cause of your hallucinations, you may need to see a psychiatrist, neurologist or general practitioner.
Treatment may involve taking medication to treat a health condition. Your doctor may also suggest that you adopt different behaviors, such as drinking less alcohol and sleeping more, to improve your hallucinations.
Common Causes of Hallucinations
Schizophrenia. More than 70% of people with this disease experience visual hallucinations and 60% to 90% hear voices. But some can smell and taste things that are not there.
Parkinson’s disease. Half of people with this condition sometimes see things that aren’t there.
Alzheimer’s disease. and other types of dementia, especially Lewy body dementia. They cause changes in the brain that can cause hallucinations. It may be more likely to occur as your disease progresses.
Migraine. About a third of people with this type of headache also have an “aura”, a type of visual hallucination. It may look like a multi-colored crescent moon.
Glioma. Depending on where it is, it can cause different types of hallucinations. If it’s in a field related to vision, you might see things that aren’t real. You can also see points of light or shapes. Tumors in certain areas of the brain can cause smell and taste hallucinations.
Charles Bonnet syndrome. This condition causes people with vision problems such as macular degeneration, glaucoma, or cataracts to see things. At first you may not realize it was a hallucination, but eventually you realize what you see isn’t real.
Epilepsy. The seizures that accompany this disorder can make you more likely to have hallucinations. The type you get depends on which part of your brain the seizure is affecting.
Types of hallucinations
Hallucinations can affect your vision, smell, taste, hearing, or bodily sensations.
Visual hallucinations involve seeing things that are not there. Hallucinations can be objects, visual patterns, people, or lights.
For example, you may see flashing lights that someone who is not in the room or that no one else can see.
Olfactory hallucinations involve your sense of smell. You may feel an unpleasant odor when you wake up in the middle of the night or your body smell bad when you wake up.
This type of hallucination can also include odors that you like, such as the scent of flowers.
Gustatory hallucinations are similar to olfactory hallucinations, but involve your sense of taste rather than smell.
These flavors are often strange or unpleasant. Gustatory hallucinations (often with a metallic taste) are a relatively common symptom for people with epilepsy.
Auditory hallucinations are among the most common types of hallucinations. You may hear someone talking to you or telling you to do certain things. The sound can be angry, neutral, or hot.
Other examples of this type of hallucination include hearing noises such as someone walking in the attic or repetitive clicking or tapping sounds.
Tactile hallucinations involve the sensation of touch or movement in your body. For example, you may feel insects crawling on your skin or your internal organs moving. You can also feel the imaginary touch of someone’s hands in your body.