Hallucinations: What Causes Them and When to Get Help

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 voice that no one else in the room can hear, or you may see an image that is not real.

Mental illnesses, side effects of medications, or physical illnesses such as epilepsy or alcohol use disorder can cause hallucinations. When comparing hallucination vs. delusion, it's important to understand that hallucinations involve false sensory experiences, while delusions are false beliefs held despite evidence to the contrary. In contrast, hallucination vs illusion refers to the difference between perceiving something that isn't there (hallucination) versus misinterpreting a real stimulus (illusion).

Types of Hallucinations

Visual Hallucinations

Visual hallucinations involve seeing objects or scenes that are not present. Common examples include seeing people, animals, or shapes that others do not see.

Auditory Hallucinations

Auditory hallucinations are characterized by hearing sounds, voices, or conversations that are not real. This is one of the most common types of hallucinations and can be distressing.

Olfactory Hallucinations

Olfactory hallucinations involve smelling odors that do not exist. These smells may be pleasant or unpleasant and can cause confusion and discomfort.

Tactile Hallucinations

Tactile hallucinations refer to the sensation of physical contact or movement on the skin that is not actually happening. For instance, a person may feel bugs crawling on their skin.

Gustatory Hallucinations

Gustatory hallucinations involve tasting something that isn't actually in the mouth. This can result in strange or unpleasant taste sensations.

Causes of Hallucinations

• Schizophrenia: Over 70% experience visual hallucinations; 60-90% hear voices. May also involve smells and tastes.
• Parkinson's disease: Up to half may see things that aren't real.
• Alzheimer's disease: Especially in forms like Lewy body dementia, brain changes can cause hallucinations.
• Migraines: Around one-third may have visual “aura” hallucinations.
• Brain tumour: Location-dependent, may cause various types of hallucinations.
• Charles Bonnet syndrome: Occurs in those with vision loss, leading to visual hallucinations.
• Epilepsy: Seizures may trigger hallucinations based on the brain area affected.
• Sensory diseases: Vision or hearing loss can lead to hallucinations.
• Dementia and brain disorders: Often involve emotionally charged hallucinations in later stages.
• Drugs: Hallucinogens (LSD, DMT, mushrooms) distort perception and can cause hallucinations.

Temporary Causes of Hallucinations

• Sleep deprivation: Especially extreme fatigue can lead to visual/auditory hallucinations.
• High fever: Can cause delirium and hallucinations, especially in kids or the elderly.
• Alcohol or drug use: Intoxication or withdrawal (e.g., benzodiazepines) can provoke hallucinations.
• Medications: Painkillers, sedatives, or anticholinergics may cause hallucinations at high doses.
• Delirium: Triggered by infection, dehydration, or post-surgery.
• Extreme stress/anxiety: May lead to brief auditory or visual hallucinations.
• Migraines: Visual aura may precede or accompany the headache.
• Sensory deprivation: In darkness or silence, the brain may generate hallucinated input.

Short-term hallucinations typically improve after resolving the underlying issue. However, recurring or persistent hallucinations should be evaluated by a medical professional.

Symptoms of Hallucinations

• Seeing or hearing things that are not there
• Feeling sensations on the skin that aren't real
• Experiencing unusual tastes or smells
• Feeling confused or distressed
• Difficulty distinguishing between reality and hallucinations

When to Visit a Doctor

See a doctor after any hallucination, even a single episode. It's especially important if:

• There's a pre-existing condition like schizophrenia or Parkinson's
• Hallucinations worsen or change
• There are mood or behavior changes

Although not all hallucinations require emergency care, only a healthcare provider can assess the seriousness.

How to Diagnose Hallucinations

Your healthcare provider may perform the following:

• Blood tests to identify metabolic or toxic causes
• Electroencephalogram (EEG) to detect abnormal brain activity
• Magnetic resonance imaging (MRI) for tumors, strokes, or structural issues

Treatment for Hallucinations

Treatment depends on the root cause and may include:

• Medication: Antipsychotics such as risperidone or olanzapine
• Therapy: CBT or psychotherapy to manage and understand hallucinations
• Addressing underlying conditions: Managing epilepsy, substance use, etc.
• Supportive care: Calm environments and stress reduction techniques

Can Hallucinations Be Prevented?

While not all hallucinations can be prevented, coping strategies and support can help reduce their impact:

• Hum or sing a song
• Listen to music
• Read (forward or backward)
• Talk to someone
• Exercise regularly
• Ignore voices when possible
• Follow medical treatment plans consistently