What are the warning signs of head and neck cancers?

Common ones. Common signs can be a tip off for underlying head/neck cancer. A sore throat that gets worse despite antibiotics, a neck lump that keeps growing, voice hoarseness that get worse despite rest and therapy, or difficulty swallowing that gets worse are some common situations. General signs (major tiredness, unintentional weight loss) can happen. In pts with smoking & alcohol use the are more worrisome.
Avoid tobacco & etoh. Early warning signs are - lump in the neck., change in the voice, painless growth in the mouth, bringing up blood, swallowing problems, changes in the skin, constant pain in or around the ear when you swallow can be a sign of infection or tumor growth in the throat. This is particularly serious if it is associated with difficulty in swallowing, hoarseness, or a lump in the neck. Check with ENT doc.