Another name you may here is tinea unguinum. This is the same thing. The nails will turn much whiter than they usually are, will get thick and chalky and sometimes crumbly. There is no particular reason why you got this. It doesn t mean that something else is wrong with you.
Nail fungus is very common.
Anti-fungal creams will not help. It has to be treated with pills. Two of the most common pills used are itraconazole and terbinafine. Your doctor will give you a prescription, which you should follow. Treatment can take anywhere from 6 weeks up to 3 months.