12 Surprising Causes of Spoon-Shaped Nails (Koilonychia)

7. Raynaud’s Disease

Raynaud’s disease, a condition characterized by reduced blood flow to extremities due to blood vessel spasms, can lead to koilonychia. This condition commonly affects the fingers and toes, causing them to turn white or blue when exposed to cold temperatures or stress. Chronic episodes of restricted blood flow deprive the nail beds of oxygen and essential nutrients, potentially leading to spoon-shaped nails. Individuals with Raynaud’s may notice other symptoms like numbness, tingling, and a cold sensation in their extremities. Addressing the underlying vascular issues through lifestyle changes or medications to improve circulation can help reduce the likelihood of developing nail abnormalities.

8. Celiac Disease

Celiac disease, an autoimmune disorder triggered by gluten ingestion, can indirectly cause koilonychia. This condition damages the lining of the small intestine, impairing the absorption of essential nutrients such as iron, zinc, and B vitamins. The resulting nutrient deficiencies, particularly iron deficiency anemia, are strongly associated with spoon-shaped nails. Other symptoms of celiac disease include gastrointestinal discomfort, fatigue, and skin rashes. For patients with celiac disease, adhering to a strict gluten-free diet is critical to restoring nutrient levels and promoting overall health, which can improve the appearance of the nails.