What are the signs of an infected tooth or gums if theres no swelling?

Tooth/gum infxn: Even if there's no swelling, there may be redness or bleeding when brushing, pain when chewing, altered sense of taste, facial pain, headache, sinus problems, bad breath. Best to make appt with dentist for checkup & treatment.

Blood in saliva.: A dental or periodontal infection can demonstrate unnoticeable swelling in its early stages. If your gums bleed when you floss you have at minimum an inflammation and possible infection. If you have one or more teeth that are lose you probably have an infection. If you have pain when you bite you may have an early dental infection. See your dentist if you suspect you may have an infection.

Pain & bleeding: An infected tooth or gums may not cause swelling if fluids from it are resorbed, drain, dissipate in some other way. Classic signs of infection are : pain, redness, swelling and bleeding amongst other signs, see a dentist as soon as possible.