A red tongue
A healthy tongue should be pink, not red. If your tongue is red, it could be a sign of a vitamin deficiency, particularly folic acid or vitamin B12. In order to test for a deficiency, you can get a blood test done.
Another possible reason for a red tongue is scarlet fever. Scarlet fever is usually caused by a bacterial infection, and the symptoms include having a red, bumpy appearance of the tongue, as well as high fever. If you notice these symptoms, it would be a good idea to get in touch with your doctor in order to seek treatment.
Kawasaki disease is another health problem whose symptoms include a red tongue. It occurs in children aged 5 and below, and is a serious health condition. Aside from a red tongue, high fever is another symptom for this disease.
Bumps or sores on the tongue
Mouth sores are normal, and usually happen as a result of trauma such as accidentally biting your tongue or scalding it. As your tongue heals you might notice some bumps or sores, but these are normal and should not be a cause for concern.
Canker sores can cause your mouth and tongue to have sores. These can be very painful, especially if you eat acidic or salty foods. For the most part, these should not be a cause for concern, and canker sores usually go away after a few days.
However, if you “read” your tongue and noted some unusual sores, bumps, or growths that seem to last for weeks, it would be a good idea to get in touch with your doctor. Mouth sores that don’t heal can be a sign of oral cancer.