7. Dark lines:
Dark vertical stripes (linear melanonychia) on the nails are at times naturally present in dark-skinned individuals. However, if it appears suddenly, it might indicate subungal melanoma. In this case, the dark stripes my change their color overtime due to variation in pigmentation. Moreover, the surrounding nail fold is also likely to darken. Fortunately in most of the cases of linear melanonychia, the underlying cause is negligible.
8. Red streaks:
If you notice any red or brown streak developing under the surface of your nail, it could be a ‘splinter hemmorhages’, which is actually the blood oozing out of a damaged underlying vessel. Splinter hemmorhages can occur due to nail trauma. It is also an important sign of endocarditis, lupus erythematosus and psoriasis.
9. Overgrown nails:
Overgrown thickened nails are a common consequence of fungal infection. Moreover, they also form a symptom of reactive arthritis and psoriasis. A condition known as ‘onychogryphosis’, in which the toe nails grow excessively long and resemble a ram-horn, must not be confused with the thickened nail occurring due to fungal infection. The latter mentioned scenario is of common occurrence in the old age group, in whom the nail overgrows as a response to long-term pressure.