Horizontal lines, known as Beau’s lines, can appear after a period of significant physical stress, serious illness, injury, or certain medical conditions. In some cases, they may also be associated with conditions such as diabetes or problems affecting blood circulation.

Vertical ridges are common as people age and are often harmless. However, if the ridges become unusually deep, irregular, or are accompanied by other symptoms, they may sometimes be linked to nutritional deficiencies, including low iron or vitamin B12 levels.

Dark streaks beneath a nail that appear suddenly or change over time should be evaluated by a healthcare professional, as they can occasionally be a sign of subungual melanoma, a rare but serious form of skin cancer. White lines, known as Muehrcke’s lines, may be associated with low protein levels or certain liver and kidney conditions, although they can also have other causes.

As people get older, it is important to pay attention to noticeable changes in the nails. While many nail changes are harmless and related to aging, persistent or unusual lines, discoloration, or changes in nail shape should not be ignored. If you notice any concerning changes, consult a healthcare provider for a proper evaluation, as nail abnormalities can sometimes provide early clues about underlying health conditions.