According to WebMD, cracks and fissures in the tongue are typically a normal variation, present in 2 to 5 percent of the population. Tongue cracks typically occur in adults and can get deeper with age. They tend to present with no symptoms.
WebMD points out that cracked tongues may be inherited genetically. According to Healthline, those with Down syndrome and Melkersson-Rosenthal have increased risks of cracked or fissured tongues.
Geographic tongue, or benign migratory glossitis, often co-occurs with fissured tongue, according to WebMD. Its only side effect is sensitivity to spicy foods. No treatment is necessary for cracked or fissured tongue though good oral care is required to keep bacteria from collecting in the cracks.