• Fingernails grow faster than toenails — especially on your dominant hand.
    • On average, fingernails grow 3.5 millimeters (mm) per month, while toenails grow an average of 1.6 mm per month. 
  • Nail growth rates depend on age, time of year, activity level, and heredity.
    • Women's nails grow more slowly than men's, except possibly during pregnancy.
    • Nails grow more rapidly in summer than in winter.
  • Nail growth is affected by disease, nutrition, medications, trauma, chronic illness, fever, and the aging process.

Nail problems

  • Nail problems make up about 10 percent of all dermatological conditions.
  • Nails often reflect our general state of health. Changes in the nail, such as discoloration or thickening, can signal health problems, including liver and kidney diseases, heart and lung conditions, anemia and diabetes.
  • Symptoms that could signal nail problems include changes in color, shape, and/or thickness, swelling of the skin around the nails, bleeding or discharge, and pain.
  • Nail problems usually increase throughout life and affect a high number of senior citizens.
  • Fungal infections cause about half of all nail disorders. They are more common in toenails because the toes often are confined to a warm, moist, weight-bearing environment.
  • Although rare, melanomas can grow under the nail. Such melanomas may be mistaken for an injury, so you should consult a dermatologist if a dark-colored streak appears within the nail plate, if the nail discoloration does not gradually improve, or if the size of the streak increases over time.
  • Other common nail problems include:
    • White spots that appear after an injury to the nail.
    • Vertical lines, known as splinter hemorrhages, under the nails that are caused by nail injury or certain drugs or diseases.
    • Bacterial infections, most often due to injury, poor skin hygiene, nail biting, finger sucking, or frequent exposure to water.
    • Ingrown toenails, which are caused by improper nail trimming, poor stance, digestive problems, or tight shoes. 

Tips for keeping nails healthy

  • Keep your nails clean and dry to prevent bacteria from collecting under the nail.
  • Cut your fingernails and toenails straight across and rounded slightly in the center. This keeps your nails strong and helps avoid ingrown toenails.
  • When toenails are thick and difficult to cut, soak feet in warm salt water (one teaspoon of salt per pint of water) for five to 10 minutes, then apply urea or lactic acid cream. This softens the nails, making them easier to trim. 
  • Wear proper-fitting shoes and alternate shoes on a regular basis. Tight shoes can cause ingrown toenails.
  • Do not try to self-treat ingrown toenails, especially if they are infected. See a dermatologist.
  • Do not bite your fingernails. You can transfer infectious organisms between your fingers and mouth. Also, nail biting can damage the skin around your fingers, allowing infections to enter.
  • Nail problem are more common if you have diabetes or poor circulation. At the first sight of a problem, see a dermatologist. 

Nail salon safety

  • Most nail salons follow strict sanitation guidelines, but consumers should check to make sure that the salon, the manicure stations, and the implements are clean and that the technicians wash their hands between clients.
  • Consumers who get frequent manicures and pedicures should bring their own implements to the salon.
  • Don't let a nail technician cut or push back your cuticle. It might allow an infection to develop.
  • If you have itching, burning, or any type of allergic reaction to a nail cosmetic, see a dermatologist.

See your dermatologist for successful diagnosis and treatment of nail problems.

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