• Diabetes. A research study has shown that individuals with pre-existing diabetic conditions are more likely to either have, or be more susceptible to periodontal disease. Periodontal disease can increase blood sugar levels which makes controlling the amount of glucose in the blood difficult. This factor alone can increase the risk of serious diabetic complications. Conversely, diabetes thickens blood vessels and therefore makes it harder for the mouth to rid itself of excess sugar. Excess sugar in the mouth creates a breeding ground for the types of oral bacteria that cause gum disease.
• Heart Disease. There are several theories which explain the link between heart disease and periodontitis. One such theory is that the oral bacteria strains which exacerbate periodontal disease attach themselves to the coronary arteries when they enter the bloodstream. This in turn contributes to both blood clot formation and the narrowing of the coronary arteries, possibly leading to a heart attack.

The article suggests that patients whose bodies react to periodontal bacteria have an increased risk for heart disease.

It's possible that inflammation caused by this infection worsens pre-existing conditions and swells the arteries, which could lead to worse symptoms such as chest pain or shortness of breath in some cases.

• Pregnancy Complications. Women in general are at increased risk of developing periodontal disease because of hormone fluctuations that occur during puberty, pregnancy and menopause. Research suggests that pregnant women suffering from periodontal disease are more at risk of preeclampsia and delivering underweight, premature babies.
• Periodontitis increases levels of prostaglandin, which is one of the labor-inducing chemicals. Elevated levels prostaglandin may trigger premature labor, and increase the chances of delivering an underweight baby. Periodontal disease also elevates C-reactive proteins (which have previously been linked to heart disease). Heightened levels of these proteins can amplify the inflammatory response of the body and increase the chances of preeclampsia and low birth weight babies.
• Respiratory Disease. Oral bacterium linked with gum disease has been shown to possibly cause or worsen conditions such as emphysema, pneumonia and Chronic Obstructive Pulmonary Disease (COPD).  Oral bacteria can be drawn into the lower respiratory tract during the course of normal inhalation and colonize, causing bacterial infections. Studies have shown that the repeated infections which characterize COPD may be linked with periodontitis.

Along with the bacterial risk, inflammation in gum tissue can lead to severe lung damage. Individuals who suffer from chronic or persistent respiratory issues generally have low immunity which means bacteria are able to colonize beneath their gums unchecked by body’s immune system.