An infected nail becomes thicker and harder to penetrate, thus making it more difficult to treat. Filing the nail may cause even more damage, so the best approach is to treat the infection as early as possible.
While major trauma to the nail is an obvious cause of thickening, it is more often due to everyday activities creating repetitive pressure on the nail. This continual striking of the nail against the shoe causes it to separate from the nail bed. Certainly we expect to see this in long-distance runners or soccer players, but ordinary walkers are just as susceptible. The likelihood of this occurring is multiplied when distance is increased, trainers are too small, or walking routes include steep inclines.
Thickened toenails can be painful, difficult to cut and increase one’s susceptibility to infection.