The form of the language
1. A thin tongue can indicate that you have problems with dehydration and metabolism.
2. A swollen tongue may indicate that you have problems with thyroid or infection.
3. A thick tongue may indicate that you lack vitamin B1.

lines
1. The curved line may be indicative of problems with the spine. If the bow is near the bottom of the tongue, you may have back problems.
2. If you notice the torsion is in the center, you are likely to have problems with the chest area.
3. If it occurs near the tip of the tongue, you may have cervical problems.
4. In the picture, there is an inflammatory state of the tongue, where spots are observed, which may be a sign of hormonal disorders and vitamin B2 deficiency.
5. This state of the language can mean anxiety and fear. It is also a sign of Parkinson's disease.
6. In most cases, such a form of language is inherited. It can occur with Melkersson-Rosenthal syndrome (rare neurological disorder).
Note: If you have any of the above symptoms, do not diagnose yourself, but consult your doctor.
Source: Medicine.net, Bright Side