There are two main types of periodontal disease.
On the one hand, there is gingivitis. It is the inflammation of the gum at the neck of the teeth. It often results in discomfort and bleeding, but it is a milder form of gum disease.
On the other hand, periodontitis, commonly referred to as gum disease, is, however, a serious gum infection that damages the soft tissue and the bone around teeth and, without treatment, can result in the permanent loss of teeth. Mild or moderate periodontitis occurs when there are 4-6mm pockets between the teeth and soft tissues, which leads to the growth of bacteria. Advanced periodontitis occurs when the pockets have exceeded 6 mm, and this can result in significant bone loss and shifting of the teeth. Periodontitis is the most common cause of tooth loss among adults. Missing teeth is a sign of significant bone loss, and therefore advanced treatments are used to assist in improving the attachment of teeth to the jawbone and restoring their function.
In any case, it is strongly advised to book an appointment with a periodontist as soon as you notice the first symptoms of a periodontal disease, as doing so will greatly limit the likelihood of any further damage to your teeth and gum.