Healthline states that earaches can occur for a number of reasons, some of which are earwax blockage, middle ear infections, ear drum rupture, chlorine poisoning, acoustic neuroma and Bell's palsy. Neck pain may be caused by poor posture or wear-and-tear arthritis, according to the Mayo Clinic. Persons experiencing both ear and neck pain at the same time are likely experiencing either arthritis or two unrelated conditions.
The most serious medical condition that has ear pain as a potential symptom is chlorine poisoning. Healthline states that chlorine poisoning is a medical emergency and that persons who may be experiencing chlorine poisoning should seek medical assistance immediately. Ear pain may have a number of sources other than the aforementioned, including a sore throat, a sinus infection, having shampoo or water in the ear and the use of cotton swabs in the ear.
One potential common illness that causes both ear and neck pain is arthritis. If arthritis affects both a person's jaw and neck, they experience pain in both. In other situations the ear and neck pain are most likely unrelated. The leading cause of neck pain is poor posture, according to the Mayo Clinic. Poor posture results from slouching, sleeping in an uncomfortable position or otherwise putting unnecessary strain on the neck.