A metallic taste in the mouth, also known as dysgeusia, can be caused by a variety of factors. Common causes include poor oral hygiene leading to dental issues like gum disease or tooth infections, certain medications (antibiotics, antihistamines, blood pressure drugs), infections such as sinus or upper respiratory infections, vitamin deficiencies (B12, zinc), pregnancy, exposure to chemicals like lead or mercury, and medical conditions such as kidney or liver disease, acid reflux, or neurological disorders. In some cases, dental work involving metal fillings or crowns can also produce this metallic flavor. Treatments depend on addressing the underlying cause, maintaining good oral hygiene, staying hydrated, and consulting a healthcare provider if the taste persists or is bothersome.