Fungal infections can affect any part of the body. When a fungus begins to overgrow, you can get an infection. Onychomycosis is a fungal infection that affects either the fingernails or the toenails. It begins as a white or yellow spot under the tip of your fingernail or toenail. As the fungal infection goes deeper, nail fungus may cause your nail to discolour, thicken and crumble at the edge. Nail infections occur more often in men than in women, and they are found in adults more often than in children. Nail fungus is typically caused by a dermatophyte fungus. Yeasts and moulds also can be responsible for nail fungal infections. You’re more likely to develop a fungal infection if you – Symptoms of nail fungus include – If the condition is mild and does not bother you, you may not need treatment. If the nail fungus is painful and has caused the nail to thicken, self-care steps and medication may help. Even often successful treatment, nail fungus could come back. If self-care strategies and over-the-counter products haven’t helped, your doctor may suggest a combination of prescription drugs and other approaches.