There is currently no physical or lab test that can absolutely diagnose schizophrenia - a psychiatrist usually comes to the diagnosis based on clinical symptoms. What physical testing can do is rule out a lot of other conditions (seizure disorders, metabolic disorders, thyroid disfunction, brain tumor, street drug use, etc) that sometimes have similar symptoms.
Current research is evaluating possible physical diagnostic tests (such as a blood test for schizophrenia, special IQ tests for identifying schizophrenia, eye-tracking, brain imaging, 'smell tests', etc), but these are still in trial stages at only a few universities and companies and are not yet widely used. It will likely be a few years before these on the market, and adopted by hospitals, etc.
People diagnosed with schizophrenia usually experience a combination of positive (i.e. hallucinations, delusions, racing thoughts), negative (i.e. apathy, lack of emotion, poor or nonexistant social functioning), and cognitive (disorganized thoughts, difficulty concentrating and/or following instructions, difficulty completing tasks, memory problems). Please refer to the information available on this page (see below) for common signs and symptoms, as well as consumer/family stories of how they identified schizophrenia in their own experiences. However, only a psychiatrist can make a diagnosis and start a treatment program. If you are experiencing symptoms are bothersome, debilitating, or harmful, please to to an early psychosis diagnosis and treatment center or make an appointment with your doctor and/or a psychiatrist.
The First Steps Towards Proper Diagnosis
The first step in getting treatment for schizophrenia is getting a correct diagnosis. This is important to do quickly because research has shown that the sooner you get diagnosed and treated, the better the long-term outcome (which is the same for all serious illnesses). This can be a more difficult than it