Hallucinations are sensory experiences where a person perceives things that are not actually present, affecting any of the senses including hearing, seeing, smelling, tasting, or feeling sensations

Causes of Hallucinations

Hallucinations can arise from a wide range of causes, primarily involving mental health conditions, neurological disorders, substance use, and physical illnesses:

• Mental health conditions: Schizophrenia is the most common cause, with many patients experiencing auditory (hearing voices) and visual hallucinations. Other conditions include bipolar disorder, psychotic depression, dementia (including Lewy body dementia), and delirium

• Neurological disorders: Parkinson’s disease, Alzheimer’s disease, brain tumors, epilepsy (especially temporal lobe epilepsy), migraines, and stroke can cause hallucinations due to brain tissue damage or irritation

• Substance use and withdrawal: Use of or withdrawal from drugs such as marijuana, LSD, cocaine, PCP, amphetamines, heroin, ketamine, and alcohol can induce hallucinations. Delirium tremens, related to alcohol withdrawal, is a notable cause

• Sensory impairments: Loss or change in vision (e.g., Charles Bonnet syndrome) or hearing can trigger hallucinations, especially visual ones in people with deteriorating eyesight

• Physical illnesses and conditions: Fever, infections, severe illnesses (like liver failure, kidney failure, HIV/AIDS, brain cancer), and post-surgical states including anesthesia can cause hallucinations, often due to delirium or brain dysfunction

• Sleep-related: Lack of sleep or sleep disorders can cause hypnagogic (before sleep) or hypnopompic (upon waking) hallucinations

• Medications: Certain medications for Parkinson’s disease, depression, psychosis, and epilepsy may have hallucinations as side effects

In summary, hallucinations are caused by disruptions in brain function due to psychiatric illnesses, neurological damage, substance effects, sensory loss, physical illness, sleep disturbances, or medication side effects