Changes in your nails can sometimes reveal important clues about your health, especially after age 40. Paying attention to unusual lines or patterns may help detect underlying conditions early.

Horizontal lines, known as Beau’s lines, can appear after periods of illness, intense stress, or chronic conditions like diabetes or circulation problems. These lines often reflect a temporary disruption in nail growth.

Vertical ridges are common as part of natural aging. However, if they become very deep or uneven, they may point to nutritional deficiencies, particularly low iron or vitamin B12 levels.

Dark streaks under the nail should never be ignored. Their sudden appearance may be a warning sign of melanoma, a serious form of skin cancer, and requires immediate medical evaluation.

White lines, called Muehrcke’s lines, can be linked to liver or kidney issues or low protein levels in the body.

Bottom line: “After age 40, changes in your nails—especially unusual lines—should not be ignored.” They can act as early warning signs, so if you notice anything unusual, it’s important to consult a healthcare provider.