Abcess under my tongue, should i be concerned?

Absolutely: The abscess can travel down your neck into your chest causing severe problems. If your tongue swells enough it can block your airway and you can choke. Please see a physician immediately.

Any swelling: In your mouth should raise a concern. It may or may not be an abscess. Regardless, any infection can spread, cause serious complications and be potentially life threatening. See your dentist as soon as possible! if symptoms worsen, especially fever, trouble breathing or swallowing, have someone take you to er of hospital or 24/7 medical facility.

It depends...: ...On what's causing the abscess. First, be sure it's an abscess and not something else. It may be due to an infected tooth, in which case you should see a dentist for a root canal or an extraction. It may be due to an obstructed salivary gland duct due to a stone or stricture, or it could be caused by a ranula, a salivary gland cyst. See an oral surgeon for evaluation and treatment.