The following signs and symptoms should be investigated if they persist for more than three weeks, and especially if more than one symptom is present:

• mouth ulcer or mass
• unexplained tooth mobility and/or non-healing dental extraction site
• white or red patches of oral mucosa (leukoplakia)
• persisting lip ulcers or patches
• changes in the voice, such as hoarseness
• persistent sore throat (particularly together with earache) or cough
• difficulty or pain when swallowing or chewing
• coughing up blood (including spitting up blood)
• persistent unexplained neck or parotid lump or sore
• pain, pressure, unilateral ringing in the ear, or hearing loss
• unilateral paralysis of the muscles in the face
• unilateral numbness, tingling, pins and needles or formication (feeling of insects crawling on the skin)
• unilateral blockage of the nose, especially if associated with swelling or other problems with the eyes such as double vision
• trismus (lockjaw) or reduced jaw opening
• unexplained weight loss.

The presence of multiple signs and symptoms, particularly in combination with other underlying risk factors, indicates an increased risk of head and neck cancer.