Viral infections, such as the common cold, influenza, mononucleosis, chicken pox, measles and croup can cause sore throats, according to Mayo Clinic. The Mayo Clinic notes that bacterial infections, such as strep throat, whooping cough and diptheria, can also cause sore throats.
Another common cause of a sore throat is acid reflux disease, according to WebMD. WebMD explains that when stomach acid rises up into the esophagus, the throat can become irritated and sore. This is often an overlooked cause of sore throats, and when other symptoms are absent, acid reflux should be considered, according to WebMD. In addition to sore throat, acid reflux can also cause a dry cough and the feeling as though a lump is in the throat, according to WebMD. WebMD notes that lifestyle changes such as limiting coffee and alcohol and consuming a high-protein diet may help relieve symptoms.
According to the American Academy of Otolaryngology - Head and Neck Surgery, post-nasal drip is also associated with a sore throat. Post-nasal drip refers to mucus from the nose that drips down and accumulates in the throat. While there is no infection present, the tissues of the throat, including the tonsils, become inflamed. This inflammation often causes throat discomfort or a feeling as though there is a lump in the throat, according to the American Academy of Otolaryngology - Head and Neck Surgery. The American Academy of Otolaryngology - Head and Neck Surgery notes that while antihistamines may provide relief from post-nasal drip, they sometimes cause post-nasal drip mucus to become even thicker and more irritating.
Several irritants can also cause throat irritation, including outdoor and indoor air pollution, chemicals, tobacco smoke, eating spicy foods and drinking alcohol, states Mayo Clinic. People who are HIV-positive may have a secondary infection that causes a chronic sore throat.
Those who have asthma, diabetes, heart disease or are pregnant may have a higher risk of complications due to viral or bacterial infections from a sore throat, notes WebMD. Contact a health care provider if a sore throat has not gone away after three days, or if there is a fever higher than 100.4 degrees Fahrenheit for two days or longer.