What is Koilonychia?

The nails on a person’s fingers are supposed to be convex. Instead, a person with koilonychia will have concave nails. This condition is also referred colloquially as spoon nails because the person’s nails resemble a spoon-like shape. The edges will also become upturned at both the distal and lateral margins so that they can be very easily peeled off.

The depression in the nails can be deep enough that a droplet of water can be held within the space without flowing out. Furthermore, koilonychia affects more than the fingers, but the toes too, which also experience the same symptoms. [1]

koilonychia photo

How healthy nails look like?

Signs and Symptoms of Koilonychia

The main sign is, of course, the concavity if the nails, which gives them the spoon shape, but there are other symptoms that may occur besides that:

  • Loose nails that can easily be detached or come off
  • Soft and brittle nails
  • Nails with edges that seem embossed
  • Signs of malnourishment
  • Anemia and other conditions that indicate iron deficiency

These symptoms are simply a sign of an underlying condition that needs to be further diagnosed and tested by a doctor to establish the root cause. [2]


How Koilonychia develops?

The main reason why koilonychia develops is due to a deficiency of iron in the body, which leads to the symptoms above. Iron is a crucial element in the body of any living thing, especially in human beings. First and foremost, iron forms part of hemoglobin and the red blood cells on which the hemoglobin lies.

The hemoglobin is responsible for binding to oxygen in the alveoli from where it is transported to cells and binds to the waste carbon dioxide which is brought back to the alveoli for expulsion.

Iron is also found in large quantities in the liver of animals, and that’s because it plays a major role in the conversion of sugar to energy.

The liver convert stored glycogen in the body into glucose which is metabolised to produce energy. Without enough iron, the body can’t create enough glucose, which leads to the symptoms of fatigue and general weakness.

However, the body loses a lot of iron in various ways, mainly through the destruction of old red blood cells and the creation of new ones. In women, they lose even more during menstruation, requiring more iron intake. If there is not enough iron being supplied through proper diet into the body, the amount of iron in the blood drops and all the above functions begin to fail.

When there is an insufficient supply of energy, the body’s extremities are the first to go, and these include the fingers and toes. This is what causes the brittleness and change in shape of the nails in the fingers and toes. A continued lack of iron will only worsen the symptoms and affect even more body parts, which is why an individual suffering from koilonychia needs urgent care.[3]

Causes of Koilonychia

The causes of koilonychia are the same as those that lead to iron deficiency since one leads to the other. There are various reasons an individual can lack iron in the body, for example: [4,5]


Lack of enough iron in the diet directly leads to koilonychia through the process described in the section above. Foods rich in iron include liver, dark chocolate, beans, seafood, etc. It is important to check with a nutritionist to determine the proper diet for you based on your taste and other factors.

Blood loss

This could be due to trauma through an accident, gastrointestinal blood loss due to a medical condition like a bleeding ulcer or even worms. Consistent loss of blood through any of these methods could cause koilonychia.

Other causes

Some rare causes may include celiac disease, which is an autoimmune disorder affecting 1 in 100 people worldwide and is triggered by gluten causing the body to attack the villi in the small intestines, blocking the absorption of nutrients. Exposure to petroleum products have also been known to create an iron deficiency.


The first indicators of koilonychia can be identified through a physical examination by a doctor – the concave nails are usually a major sign of the condition. Other indicators that hint toward koilonychia include signs of malnourishment, which could present as pallor, general weakness, fatigue and loss of weight.

The latter symptom can be determined through a measure of the patient’s BMI (body mass index) which compares a person’s actual weight to the recommended weight based on their height. [6]

To prove these physical symptoms, other laboratory tests are usually done to assess the amount of iron in the body. These lab tests are used to estimate the levels of leukocytes, hemoglobin and platelets in the blood, all of which are created from iron. A low concentration of these elements will indicate that the individual has not been taking in enough iron in their diet. Since iron is very common in many foods, a deficiency in iron is usually an indicator of general malnourishment.

Treatment of Koilonychia

Some more tests can also be required in order to establish the extent to which the koilonychia has affected the individual.

For example, an esophagogastroduodenoscopy can be performed to establish if the person has any internal bleeding, and it is often accompanied by a colonoscopy for the same reason. These tests are supposed to inform the doctor whether the iron deficiency is due to a lack of proper diet or an underlying bleed draining the affected individual of iron.

Once properly diagnosed by a doctor, the treatment of koilonychia is quite straightforward, and primarily involves administration of iron supplements. Of course, this would only be done once the underlying cause, if any, was first attended to.

For example, if there was an underlying bleed, surgery may be required to stop the bleed. The course of iron supplements should be taken exactly as prescribed because abusing the supplements could lead to an overload of iron. The supplements should also not be taken along with beverages containing caffeine such as coffee or tea since caffeine blocks the absorption of iron in the body. [7]

Managing Koilonychia

While on the course of treatment, there are some more precautions to take to avoid aggravating your condition or sparking off another one. Koilonychia causes the nails in the fingers and toes to be brittle and easy to peel off, and this could leave your extremities open to infection.

To avoid this, wear gloves whenever you’re doing any activity that could peel your nails off or while handling harsh chemicals. For your feet, wear shoes that do not press the toes together. [8]


koilonychia image

koilonychia images

koilonychia photos

koilonychia pics

koilonychia Pictures


  1. Nails and there types (based on shapes and sizes) Available from: http://www.scribd.com/document/101910171/ASTRO-Palmistry
  2. Koilonychia Available from: http://www.diseasepictures.com/koilonychia
  3. Nail Abnormalities Available from: http://www.healthline.com/health/nail-abnormalities-2#Overview1
  4. Nailing the diagnosis: Koilonychia. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442766/
  5. Causes of Koilonychia Availabe from: http://www.ic.steadyhealth.com/causes-of-koilonychia
  6. Koilonychia Fingernail & Toenail disorders Available from: http://www.handresearch.com/finger-nails/koilonychia-nail.html
  7. Koilonychia: Causes, Pictures, Symptoms and Treatment. Available from: http://www.healthsource4u.com/koilonychia-causes-picture-symptoms-treatment.html
  8. Under the Microscope: Koilonychia Available from: http://www.nailsmag.com/article/94835/under-the-microscope-koilonychia

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