Q. I’ve got discoloured nails on my toes and they’re getting worse – please help!
A. You probably have a fungal nail infection - these kinds of infection are very common. 
They're not serious but they can take a long time to treat – so be patient.
Fungal nail infections usually affect your toenails, but you can get them on your fingernails, too.
The best thing to do is to file thickened nails down to make them more comfortable. 
If it is difficult you may wish to see a chiropodist for your feet.
You also might want to speak to your surgery about sending your nail clippings for culture. It can take some time for the results to come back and the treatment can take up to 12 months.
The infection is cured when you see healthy nail growing back at the base.
Fungal nail infections develop when your feet are constantly warm and damp, and you are more likely to get an infection if you wear trainers for a long time or if you have hot, sweaty feet.
To prevent fungal nail infections treat athlete's foot as soon as is possible – this will help avoid it spreading to your nails. 
In addition, keep your feet clean and dry, wear clean socks every day, wear flip-flops in showers at the gym or pool and throw out old shoes.
Don't wear shoes that make your feet hot and sweaty, don’t share towels, don’t wear other people's shoes and don’t share nail clippers or scissors.