Some causes of yellow nails, like psoriasis and yellow nail syndrome, are outside of your control. In other cases, however, you can do a lot to keep your nails healthy and looking great. For instance, to lower your chance of a fungal infection, try not to expose your nails to moist, dark environments. This is particularly important for your toenails, since socks and shoes can trap in moisture and put you at risk of infection. Avoid walking barefoot around pools and showers as well, since the moisture in those environments encourages infection. And if you need another reason to quit smoking, dropping the habit can keep your nails from getting stained with nicotine.
More important than your nails' appearance, however, is what your nails are telling you about your health, so if you notice changes in the way your nails look, make sure to bring it up with your doctor.
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