Metallic Taste in Mouth (Dysgeusia): 6 Cause Categories

Dysgeusia has diverse etiologies:

1. Nutritional deficiencies: B₁₂, zinc, copper.
2. Medications: Antibiotics (metronidazole), chemo, ACE inhibitors, lithium, antihistamines.
3. Medical conditions: CKD, liver disease, diabetes, hypothyroidism, Sjögren's, GERD.
4. Oral/dental: Gingivitis, periodontitis, abscess, amalgam fillings, poor hygiene.
5. Metal exposure: Lead, mercury, copper, iron overload.
6. Other: Stress/anxiety, dehydration, pregnancy, sinusitis, radiation therapy.

Evaluation: history, medication review, oral exam, basic labs (CBC, BMP, B₁₂, zinc, TSH, LFTs). Treat underlying cause; symptomatic relief with saliva substitutes, oral hygiene, zinc if deficient.