If you have lines on your nails, it means you have c…See more

(an underactive thyroid) can also slow nail growth and make nails dry and brittle due to reduced metabolic activity.
Another well-known nail sign is spoon-shaped nails, medically called koilonychia. In this condition, the nails curve upward at the edges, forming a concave shape that can hold a drop of water.
 This is often associated with iron deficiency anemia. In some cases, it may also relate to chronic blood loss, liver disorders, or genetic conditions.
When spooning appears alongside fatigue, pale skin, or shortness of breath, a blood test is strongly recommended.
Yellow nails can have multiple causes.
Mild yellowing may