Spoon Nails (Koilonychia)

Medically reviewed by Debra Sullivan, PhD, MSN, CNE, COI on February 27, 2017Written by Marjorie Hecht on February 27, 2017

What are spoon nails?

Spoon nails are thin and soft and shaped like a little spoon that is often capable of holding a drop of water. There are many causes, but the most frequent one is iron deficiency anemia.

The medical name for spoon nails is koilonychia, from the Greek words for hollow (koilos) and nail (onikh).

Pictures of spoon nails

spoon nail

How can you identify spoon nails?

Spoon nails look like the center of your nail is scooped out. The nail becomes thin and the outer edges turn up. Your nail may crack, and the outer part may come out of the nail bed.

Some infants are born with spoon nails, but they eventually grow out of it. Spoon nails usually develop on fingernails, but they can also occur in your toenails.

The most common cause of spoon nails is iron deficiency, or anemia. This makes your level of red blood cells lower than normal. If anemia is causing your spoon nails, you may also experience:

  • fatigue
  • pale skin
  • shortness of breath
  • weakness

Spoon nails may affect just one of your nails, a few of them, or all of them.

What causes spoon nails?

The most frequent cause of spoon nails is iron deficiency anemia. But spoon nails can also result from:

  • trauma to the nail
  • chemotherapy or radiation therapy for cancer
  • frequent exposure to petroleum solvents or detergents
  • inability to absorb nutrients

Some of the diseases associated with spoon nails are:

Spoon nails can also be hereditary (genetic), or caused by your environment. One study of people who lived in a higher altitude found that over 47 percent of them had spoon nails. The study also found that residents who did manual labor had an even higher chance of developing spoon nails.

Another study found that spoon nails occurred in 32 percent of children who lived in a rural area, compared with 17 percent of urban children. The authors concluded that the rural children likely had more trauma to their feet because they walked barefoot and frequently had their feet in water.

Hairdressers may also have a risk of spoon nails caused by the petroleum-based products that they use for hair weaves and hair removal.

How are spoon nails diagnosed?

You may be able to identify spoon nails because of their appearance, but you should see a doctor to determine the cause and a proper treatment.

The doctor will physically examine you, ask about your medical history, and do blood tests if they suspect iron deficiency or too much iron.

If no systemic diseases are involved, your spoon nails may be the result of nail damage, heredity, or environmental factors. Spoon nails with no underlying systemic disease will not affect your health.

How are spoon nails treated?

If your spoon nails are associated with a specific condition, your doctor will suggest a treatment plan for that disease.

For anemia, the most frequent cause of spoon nails, your doctor will prescribe iron supplements and dietary changes so that you get more iron from foods. Be sure to follow directions on taking the iron supplements, so that your body absorbs the right amount.

If your body doesn't absorb vitamin B-12 from foods, your doctor may prescribe periodic vitamin B-12 shots.

Eat an iron-rich diet to prevent anemia. This includes:

  • red meat
  • pork
  • poultry
  • seafood
  • beans
  • dark green leafy vegetables
  • peas
  • dried fruit, such as raisins and apricots

Your body can absorb more iron from meat than from other sources. If you choose not to eat meat, you'll have to eat more vegetable and fruit iron sources. Consuming more foods with vitamin C will help your body absorb iron from food.

There are some basic things you can do to help the condition of your spoon nails:

  • Keep your nails clean and short.
  • Use a skin softener or oil to keep your nails well-lubricated.
  • Don't bite your nails.

What's the outlook for spoon nails?

How fast your spoon nails clear up depends on the cause. If your spoon nails are related to anemia, you may feel better a week or so after increasing your iron intake, but it may take months to get your body's iron up to normal.

If you are treated for other diseases that are associated with your spoon nails, your nails should clear up in time.

Fingernails grow slowly, and toenails grow even more slowly. It can take half a year for a fingernail to regrow, and a year and a half for a toenail to regrow.

What can you do to prevent spoon nails?

Keeping your nails clean and short is important to prevent spoon nails, and also to avoid infection in the damaged areas. Using a skin softener or oil on your nails after showering or bathing will help keep them in good condition.

Other preventive measures include:

  • Don't bite your nails, and don't pick at them.
  • Make sure that your shoes fit, and keep your feet clean and dry if your toenails are affected.
  • Don't use nail polish until your nails have returned to normal.
  • Wear gloves to protect your hands when working with chemicals or washing dishes.
  • Eat a nutritious diet.
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