Fingernails that split vertically are fairly common, yet typically caused by age as the cells turnover within the nail, explains Mayo Clinic. Nails that are split but also dry and brittle with cracks could be an indication of thyroid disease, according to WebMD.
Nails that are cracked and split with a yellowish tint often indicate a fungal infection that requires medical attention, explains WebMD. People whose nails change colors or develop horizontal ridges should also consult with a medical professional to determine if an underlying health condition is causing the discoloration and ridges, warns Mayo Clinic.
People can prevent nails from cracking and splitting by keeping the nails clean, trimmed, rounded and dry, explains Mayo Clinic. Harsh nail products such as polish remover should be avoided to prevent damaging the nails and cuticles.