The most common reason for toothaches is tooth decay, or cavities, and the most likely reason for tooth decay is poor oral hygiene. So if you brush your teeth only occasionally, don't floss, and don't see your dentist regularly, you are at risk for tooth decay and toothaches. Other risk factors for tooth decay, which is the most common cause of toothaches, include:
diabetes
having a weak immune system due to certain medicines (such as chemotherapy for cancer) or certain diseases (such as HIV/AIDS)
smoking
xerostomia, also called dry mouth, which may happen as a side effect of certain drugs, after injury to your head or neck, after radiation therapy, or in certain diseases such as Sjogren's syndrome
The most common reason for toothaches is tooth decay, or cavities,
and the most likely reason for tooth decay is poor oral hygiene. So
if you brush your teeth only occasionally, don't floss, and don't
see your dentist regularly, you are at risk for... More
Dr. De Vizio of Colgate answered:The most common reason for toothaches is tooth decay, or cavities, and the most likely reason for tooth decay is poor oral hygiene. So if you brush your teeth only occasionally, don't floss, and don't see your dentist regularly, you are at risk for tooth decay and toothaches. Other risk factors for tooth decay, which is the most common cause of toothaches, include: