Abnormal toenails
As we grow older our nails grow slower and become more susceptible to fungal infection. The signs include thickening and discolouration.
However, previous injury may also cause permanent abnormality of the nails. Basically, a sample of all abnormal nails should be taken and sent to the laboratory for examination and culture.
The only effective topical treatment for mild infection is amorolfine (Loceryl Nail Lacquer), which is painted on to the affected nail once weekly.
Abnormal fingernails
True fungal infection of these nails is rare. Psoriasis or the use of nail hardeners may cause the nail to separate from the underlying nail bed, causing whitening of the nail.
Keep your nails as short as possible and don't poke around under the nail and it may slowly grow back normally.
Candida
Candida (thrush) occurs around the nails of people whose hands are immersed in water for long periods of time, such as barmaids and occasionally in children who perpetually suck their thumbs.
It will start as chronic redness and swelling of the part of the skin just behind the half moon. Pressure will allow a little pus to escape from the corner of the nail. Later the nail will start to grow out discoloured.
Keeping your hands thoroughly dry may eventually fix the problem. Alternatively, your doctor may prescribe itraconazole (Sporanox) or fluconazole (Diflucan).