Fingernails: What's normal, what's not

Your fingernails — composed of laminated layers of a protein called keratin — grow from the area at the base of the nail under your cuticle. Healthy fingernails are smooth, without pits or grooves. They're uniform in color and consistency and free of spots or discoloration.

Sometimes fingernails develop harmless vertical ridges that run from the cuticle to the tip of the nail. Vertical ridges tend to become more prominent with age. Fingernails can also develop white lines or spots due to injury, but these eventually grow out with the nail.

Not all nail conditions are normal, however. Consult your doctor or dermatologist if you notice:

• Changes in nail color, such as discoloration of the entire nail or a dark streak under the nail
• Changes in nail shape, such as curled nails
• Thinning or thickening of the nails
• Separation of the nail from the surrounding skin
• Bleeding around the nails
• Swelling or pain around the nails
• Failure of nails to grow out