If you think you might have synesthesia, but aren’t sure, first see if you have any of the risk factors for it, which are being female, being left-handed, and having a relative with the same condition. Next, make sure you’re not having hallucinations, which are random and fanciful, unlike the symptoms of synesthesia, which are predictable and repeat themselves. To rule out hallucinations or other serious medical conditions, visit your doctor for a diagnosis and possible treatment.