That depends on which direction the waves are. If they are vertical, the cause is typically vitamin deficiency or aging. Horizontal are due to manicure damages (such as fake nails), illness, and physical stress. Take a visit to the dermatologist, s/he will be able to help determine the cause, as the cause can sometimes be serious especially as a smoker.
smoking
dirt
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The deep *vertical* lines in your fingernails are genetic. If you have *horizontal* ridges in your nails, you should see a doctor.
picking warts on your bum and casual worms.
Keratin... it's a natural substance that makes the nail harden.
Fingernails are normal in the human body. Please be more specific in your question.
The middle of your eye has some think stuck in it or you have a eye infection. but the most common reason why people have wavy vision because they might need glasses.
The white area in fingernails and hair are caused by air. That's why snow is white and not blue. Little bumps and bruises that are done to the bed of the nail cause these imperfections.
the size of your hair folicle --- sometimes off herdity too...
Wavy is correct.
If you are referring to wavy hair, or a wavy line, it is "ondulé/-e."