Please tell me the characteristics of schizophrenia. Is this schizophrenia?

Recently, my friend has been showing some concerning symptoms, and I am worried.

My friend often experiences hallucinations, such as hearing sounds that aren't there.

They say it feels like seeing someone who isn't there.

There are many cases where misunderstandings occur even during conversations.

There are often cases where the speech is illogical or difficult to understand.

It seems that emotional expression has become more subdued, and even when there is something joyful, I don't show much emotional reaction.

Furthermore, there is a clear tendency to avoid meeting people and to spend time alone.

I am wondering if these symptoms could possibly indicate schizophrenia.

It seems to match the symptoms of schizophrenia, and I think treatment or support might be needed.

Is it better to receive a diagnosis from a specialist?

Please advise on the best way to respond in this situation.