Nails in good condition can be very attractive. They also reflect an individual’s personal habits – good or bad. Aside from their cosmetic appeal, nails serve many important functions. They help us pick up and manipulate objects and support the tissues of the fingers and toes. Most importantly, nails often reflect our general state of health.


Nails are produced by living skin cells in the fingers and toes. They are composed primarily of keratin, a hardened protein also found in skin and hair. The nail itself consists of several different parts, including:

  • Nail Plate: The visible part of the nail on fingers and toes.
  • Nail Bed: The skin beneath the nail plate.
  • Matrix: The area under the cuticle, the hidden part of the nail unit where growth takes place.
  • Lunula: This is part of the matrix and is the whitish, half-moon shape at the base of the nail, usually most pronounced on the thumb.
  • Cuticle: Tissue that overlaps the plate and rims the base of the nail.
  • Nail Folds: The folds of skin that frame and support the nail on three sides.

Nails, like hair, grow from the matrix. As older cells grow out, they are replaced by newer ones, they are compacted and take on a hardened form. The average growth rate for nails is 0.1 mm each day; individual rates depend on age, time of year, activity level, and heredity. Fingernails grow faster than toenails. Nails also grow more rapidly in the summer than in the winter. Nails on a person’s dominant hand (right vs. left) grow faster, and men’s nails grow more quickly than women’s, except possibly during pregnancy and old age. Nail growth is affected by disease, hormone imbalance, and the aging process.

Common Nail Disorders

Due to their exposed location, nails take a lot of abuse. Nail disorders comprise about 10 percent of all skin conditions. Most of us, at one time or another, have closed fingers in doors, suffered from ingrown toenails, or endured minor nail infections. Most minor nail injuries heal on their own, although, they might be unsightly for a while due to the nail’s slow growth rate. More serious injuries or disorders may require professional treatment. Symptoms that could signal nail problems include color or shape changes, swelling of the skin around the nails, and pain. Additionally, the persistence of white or black lines, dents, or ridges in the nail should be reported to your dermatologist.

  • White Spots – White spots on the nails are very common and usually recur. These small, semi-circular spots result from injury to the base (matrix) of the nail, where nail cells are produced. They are not a cause for concern, and will eventually grow out.
  • Splinter Hemorrhages – A disruption of blood vessels in the nail bed can cause fine, splinter-like vertical lines to appear under the nail plate. Splinter hemorrhages are caused by injury to the nail or by certain drugs and diseases. However, trauma is the most common cause. Splinter hemorrhages resolve spontaneously.
  • Ingrown Nails – Ingrown toenails are a common nail problem. The great toenails are particularly vulnerable. Improper nail trimming, tight shoes, or poor posture can cause a corner of the nail to curve downward into the skin. Ingrown nails can be painful and sometimes even lead to infection. Seek treatment for the condition rather than attempting to cut away the nail yourself, as infection may result.
  • Fungal Infections – Fungal infections make up approximately 50 percent of all nail disorders and can be difficult to treat. More common in toenails than fingernails, they often cause the end of the nail to separate from the nail bed. Additionally, debris (white, green, yellow, or black) may build up under the nail plate and discolor the nail bed. The top of the nail or the skin at the base of the nail can also be affected. Toenails are more susceptible to fungal infections because they are confined in a warm, moist, weight-bearing environment. Candida or yeast infections are common in fingernails especially if the hands are always in water or if the patient is diabetic.
  • Bacterial Infections – Redness, swelling, and pain of the nail skin folds often indicate a bacterial infection. The most common cause is trauma to the nail or surrounding skin, or frequent exposure to water and chemicals.
  • Tumors and Warts – Tumors and warts can be found near any portion of the nail unit. However, the nail plate can change shape or be destroyed as a result of the tumor or wart growth. Tumors of the nail unit are classified as cancerous or non-cancerous (benign). The most common non-cancerous tumors are warts. Warts are viral infections that affect the skin surrounding or underneath the nail. They are painful and can sometimes cause limited use of the affected finger or toe. Treatment of warts usually involves freezing or chemical application for removal. If the wart or tumor extends into the nail folds or is located under the nail plate itself, dermatologic surgery may be necessary to remove it.
  • Psoriasis – Psoriasis is a chronic skin disease characterized by red, scaly patches. Approximately 10 to 50 percent of people with psoriasis, and 80 percent of people who suffer from inflammatory arthritis associated with psoriasis, also have nail problems. The most common nail problems include pitting, rippling, or discoloration of the nail, reddish-brown discoloration of the skin under the nail, separation of the nail from the nail bed, splinter hemorrhages, crumbling and/or splitting of the nail, as well as swelling and redness of the skin surrounding the base of the nail. The signs of psoriatic nail are usually most noticeable on the fingernails.

A Hard Habit To Break

Nail biting is a common problem, especially among young children. While the habit typically disappears with age, it has been linked to anxiety with older children and adults. Not only does nail biting ruin the look of the nails, it is also a good way to transfer infectious organisms from the fingers to the mouth and vice versa. Nail biting can also damage the skin surrounding the nails, allowing infections to enter and spread. How can one break the habit? Many people are cured by applying bad tasting nail polishes or liquids to the nail.

Nail Disorders

Nail disorders can affect our ability to pick up small objects, the way we walk, and our sense of touch. Infrequent in children, nail problems usually increase throughout life and affect many of the elderly. This is due to the susceptibility of the nail to fungal infections, its increased thickness with age, circulation problems, and the regular use of medications that may affect the nails.

In general, nail disorders respond very slowly to therapy because of the slow growth rate of the nail and its inability to absorb medications very well. Treatments are defined generally as surgical or non-surgical. Surgical treatment is common to remove tumors or correct structural abnormalities. Non-surgical treatments include the use of topical or oral medications.

A Window On Health

The nails can reveal much about a person’s overall health. Many diseases and serious conditions can be detected by changes in the nails. Most doctors will check the nails carefully during a physical examination. The most common health conditions and their effect on the nails are listed below:

Condition Nail Appearance
Liver Diseases White Nails
Kidney Diseases Half of nail is pink, half is white
Heart Conditions Nail bed is red
Lung Disease Yellowing and thickening of the nail, slowed growth rate
Anemia Pale nail beds
Diabetes Slight blush at the base

Nail Care

Since many nail disorders result from poor nail care, developing good nail habits early will help keep them healthy. Remember the following tips:

  • Keep nails clean and dry. This helps keep bacteria and other infectious organisms from collecting under the nail.
  • If toenails are thick and difficult to cut, soak them in warm salt water (one tsp. of salt to a pint of water) for five to ten minutes and apply a 10 percent urea cream – available at drug stores without a prescription. Trim as usual.
  • Nails should be cut straight across and rounded slightly at the tip for maximum strength. Use sharp nail scissors or clippers to do the job. Filing the nails into points will weaken them.
  • Do not remove your cuticle. It will allow infection to develop.
  • Use a “fine” textured file to keep nails shaped and free of snags.
  • Avoid biting fingernails.
  • Avoid “digging-out” ingrown toenails, especially if they are already infected and sore. Seek treatment from a dermatologist.
  • Report any nail irregularities to your dermatologist. Nail changes, swelling, and pain could signal a serious problem. A vertical black or brown streak, especially if new, should be reported to a dermatologist. This is especially important in an adult with a single nail streak and/or pigment in the cuticle area (Hutchinson’s sign). This can also be due to a benign mole, hemorrhage from trauma, or a fungal infection, but it should be evaluated by a dermatologist.