Pulmonary edema, also known as pulmonary congestion, is excessive liquid accumulation in the tissue and air spaces (usually alveoli) of the lungs. It leads to impaired gas exchange and may cause hypoxemia and respiratory failure. It is due to either failure of the left ventricle of the heart to remove oxygenated blood adequately from the pulmonary circulation (cardiogenic pulmonary edema), or an injury to the lung tissue directly or blood vessels of the lung (non-cardiogenic pulmonary edema).Treatment is focused on three aspects: firstly improving respiratory function, secondly, treating the underlying cause, and thirdly preventing further damage and assuring full recovery to the lung. Pulmonary edema, especially when sudden (acute), can lead to respiratory failure or cardiac arrest due to hypoxia. It is a cardinal feature of congestive heart failure. The term edema is from the Greek οἴδημα (oidēma, "swelling"), from οἰδέω (oidéō, "(I) swell"). Types
Classically it is cardiogenic (left ventricular) but fluid may also accumulate due to damage to the lung. This damage may be from direct external injuries or injuries mediated by high pressures within the pulmonary circulation. When directly or indirectly caused by increased left ventricular pressure, pulmonary edema may form when mean pulmonary pressure rises from the normal average of 15 mmHg to above 25 mmHg, where pulmonary fluid may form. Broadly, the causes of pulmonary edema can be divided into cardiogenic and non-cardiogenic. By convention, cardiogenic specifically refers to left ventricular causes.
However, treatment is necessary to maintain a healthy lifestyle. If left untreated
The following can occur if left untreated:

Too much gingiva exposure

Oral morbidity

Chronic infection of areas between the gums and teeth, or at the gum line

various degrees of Periodontitis - most likely due to the inability and difficulty of keeping the gingival margin and surrounding tissue clean due to the overgrowth

Improper tooth eruption and/or complete prevention of tooth eruption as a result of too much gingiva exposure

Systemic every-day troubles including functional and aesthetic problems of the mouth

Malocclusion

Treatment
Most recent methods of treatment take the form of surgeries such as oral prophylaxis, followed by post-surgical therapies to monitor, provide proper oral hygiene, and correct the deformity. Although, the nature of recurrence post-treatment is virtually unknown, let alone what type of treatment is most effective for HGF. (SOURCE 2) In some cases, there is re-growth after surgical removal of the excess gingival tissues, in others there is minimal. No cases yet have shown any particular treatment or form of medicine to permanently remove HGF.One type of procedure that can be executed is as follows: Removal of excess tissue under anesthesia through an internal bevel gingivectomy or undisplaced flap followed by gingivoplasty and continuous sling suture placements and periodontal dressing; after about a week of recovery after the surgery, remove sutures and periodically do observational evaluations to look for any signs of re-occurrence. Recent research
Some researchers suggest that HGF is transmitted as a Mendelian trait since both autosomal dominant and autosomal recessive transmission has been reported since the early 1970s.