What is the difference between hallucinations and delusions?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Hallucinations and delusions are both symptoms of altered perception, but they differ in nature. Hallucinations involve sensory experiences—such as seeing, hearing, feeling, or smelling things that aren't actually there. Delusions, on the other hand, are firmly held false beliefs that persist despite clear evidence to the contrary.

Because these symptoms can point to a wide range of underlying conditions—from sleep deprivation and medication side effects to neurological or mental health disorders—it's important to understand what may be causing them. A quick, private, AI-powered symptom check can help you identify possible causes in minutes and guide you toward the right next steps, whether that's self-care or seeing a professional. It's free, takes just a few minutes, and could bring you meaningful clarity today.

Reviewed for medical accuracy: 07/14/2026

Important Next Steps

Learn if hallucinations need urgent care today Discover causes of hallucinations versus delusions Find out if symptoms suggest psychosis See OTC options for related symptoms Find a psychiatrist for hallucinations or delusions Learn home remedies for hallucination-related stress Understand whether your symptoms need evaluation

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Explanation

Hallucinations and delusions are both symptoms that can affect how a person understands reality, but they are different in nature.

Hallucinations are like tricks on the senses. They make you see, hear, feel, or even smell things that are not actually there. For example, someone might hear voices talking to them when no one is around.
Delusions, on the other hand, are very strong beliefs that are not true or based in reality. For instance, a person might believe they have special powers or are being followed by secret agents, even when these things are not happening.

Both hallucinations and delusions can be part of mental health conditions, and it is important to talk to a healthcare provider if you or someone you know is experiencing them. If you're concerned about symptoms you're experiencing, take our free symptom checker test to better understand what might be going on and whether you should seek professional care.

(References)

Zigler E, & Levine J. (1983). Hallucinations vs. Delusions. A Developmental Approach. The Journal of nervous and mental disease, 6827252.
Carota A, & Bogousslavsky J. (2019). Neurology versus Psychiatry? Hallucinations, Delusions, .... Frontiers of neurology and neuroscience, 31220856.
Maher BA. (2006). The relationship between delusions and hallucinations. Current psychiatry reports, 19817067.

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