1. Brittle, split nails are usually linked to hypothyroidism, a condition when your thyroid works too slowly. Dry and crumbly nails also may indicate a deficiency in vitamins A, C, and the vitamin B7 also known as biotin. Another possible reason for this nail problem is the overuse of nail polish remover.
2. Vertical ridges are usually a normal sign of aging, just like wrinkles on your face. But if they become more prominent at a young age, this may mean that you suffer from vitamin B12 or a magnesium deficiency.
3. Horizontal ridges (or Beau’s lines) are typically the result of direct trauma to your nail. However, if you see them on more than one nail at a time, they may also be a sign of a serious illness with a high fever such as scarlet fever or pneumonia.
4. Nail pitting may indicate skin problems such as psoriasis, eczema, and dermatitis. It may also be an early sign of connective tissue disorders including inflammatory arthritis, a disease that affects your joints.
