Nails that become thick due to a fungal infection normally require prescription medication for treatment, according to MedlinePlus. Over-the-counter creams are generally not effective. If the medication does not cure the fungus, doctors sometimes recommend laser treatment or surgical removal of the nail.
The doctor examines the nails and sometimes takes scrapings from thickened nails for examination under a microscope to confirm the diagnosis, reports MedlinePlus. If the examination is inconclusive, he sometimes orders growth of a culture from the nail scrapings, a process that takes about three weeks.
Patients take the prescription medication for a nail fungus daily for three months, indicates MedlinePlus. In order to get rid of the thickened nail, the body must grow a new nail, and the process sometimes requires up to a year. Because the medication potentially damages the liver, the doctor often orders regular laboratory tests to check for problems.
Fungal infections are hard to treat and do not always respond to medication, warns MedlinePlus. Even if the treatment is successful, the infection sometimes returns and causes the nail to thicken again. To prevent a fungal infection, keep hands and feet clean and dry. Avoid sharing manicure and pedicure tools, including nail clippers.