12 Surprising Causes of Spoon-Shaped Nails (Koilonychia)

6. Hypothyroidism

Hypothyroidism, a condition where the thyroid gland underproduces essential hormones, can contribute to the development of koilonychia. The thyroid gland plays a critical role in regulating metabolism and maintaining healthy tissues, including the nails. A sluggish thyroid slows down the body’s ability to repair and regenerate cells, leading to brittle and spoon-shaped nails. Patients with hypothyroidism often experience additional symptoms such as fatigue, weight gain, and hair thinning. The decreased circulation and reduced delivery of essential nutrients to the nail bed in hypothyroid individuals can exacerbate this condition. Treating hypothyroidism with hormone replacement therapy often resolves associated nail deformities over time.