Unlike Alzheimer’s, where brain imaging, blood tests, and sometimes lumbar punctures may help confirm the diagnosis, LBD cannot be definitively diagnosed in living individuals — instead, clinicians rely on detailed medical history, symptom evaluation, and a collection of clinical features and biomarkers. A major challenge is symptom overlap: up to half of LBD cases may be misdiagnosed in clinical settings. Hallucinations in a person with very early dementia should make doctors suspicious that the patient does not have Alzheimer’s but Lewy body disease, since hallucinations typically appear later in Alzheimer’s but early in LBD.