Persistent bad breath or a bad taste in the mouth may be a warning sign of gum (periodontal) disease. Gum disease is caused by the buildup of plaque on teeth. Bacteria cause toxins to form, which irritate the gums. If gum disease continues untreated, it can damage the gums and jawbone.

• Halitosis is caused by sulphur-producing bacteria in the tongue and throat.
• The major causes include a dry mouth caused by certain foods, smoking, poor oral hygiene and a coated tongue.
• The treatment of halitosis will depend on the underlying cause.
• The uneven surface of the tongue

• A white coating on the tongue especially at the back of the tongue.
• Dry mouth.
• Build up around teeth.
• Post-nasal drip, or mucous.
• Morning bad breath and a burning tongue.
• Thick saliva and a constant need to clear your throat.
• Constant sour, bitter metallic taste.