The two most common things that have the potential to cause tongue swelling are injuries to the tongue and allergic reactions. In addition, certain illnesses can lead to tongue swelling, including scarlet fever, among others. It’s also possible for the taste buds to become inflamed for various reasons. Some of the problems that make the tongue swell are considered dangerous, so it is often important for people suffering from an unexplained swollen tongue to see a physician and make sure nothing serious is going on.
A person’s tongue can easily become swollen because of injuries. For example, if someone bites down on his tongue while eating or after suffering a fall, it wouldn’t be unusual for the tongue to swell. Another common injury is to burn the tongue while eating something that’s too hot. Most of these injuries will heal on their own without any need for medical attention, and most people know why their tongues are swelling when it happens due to an injury.
A potentially serious danger that could trigger tongue swelling is any kind of allergic reaction. Sometimes these can be relatively minor and may involve the body reacting badly to something that touches the tongue's surface. In other cases, tongue swelling because of allergies can be more serious and potentially deadly.
A common and dangerous allergy that triggers tongue swelling is the inability to tolerate peanuts. Sometimes people with this allergy can suffer severe internal and external swelling, including in the tongue. If the tongue swells too much, it can actually inhibit breathing and make someone suffocate. There are many other kinds of food allergy that can potentially have this sort of dangerous reaction. Some people also suffer with tongue swelling because of the medicine they’re taking, and this could result in the same kind of dangerous reaction in some situations.
A condition known as transient lingual papillitis sometimes causes tongue swelling. This usually just gives people small and painful sores on the tongue, but they can be severe enough to make the whole tongue swell in certain cases. The condition can often be very painful, but it's not normally dangerous.
Anything that causes tongue swelling can potentially be fairly difficult for people to deal with from a practical perspective. The tongue is used for very important daily activities like talking and eating food, which are both difficult to avoid. If anything goes wrong with the tongue, it can be very emotionally irritating, especially if there is significant pain involved.