From the photos and your description, the redness and swelling appear to be localized to the gum around the lower front teeth. The most common cause is localized gum inflammation (gingivitis) due to plaque or tartar accumulation. Sometimes, chronic irritation, trauma from brushing, or an underlying periodontal pocket can also cause one area of the gum to become enlarged and red.
Since you’ve noticed that it has become larger and redder recently, I would recommend not ignoring it. Please visit a dentist or periodontist for a clinical examination. A professional scaling and cleaning may be all that’s needed if it is due to plaque-induced inflammation. However, if the swelling persists after cleaning, your dentist may advise an X-ray and, if required, further evaluation to rule out other gum growths or periodontal problems.
Next Steps
In the meantime:
* Brush gently but thoroughly twice a day.
* Clean between your teeth daily using floss or an interdental brush.
* Rinse with warm salt water 2–3 times a day.
* Avoid picking or pressing the swollen area.
If you notice pus discharge, severe pain, fever, rapid increase in size, or spontaneous bleeding, seek dental care as soon as possible.
From the photos, it looks more like a localized inflamed gum tissue rather than anything alarming, but a clinical examination is needed to confirm the diagnosis and provide the appropriate treatment.