Many people put a lot of effort into keeping their nails perfectly trimmed, cleaned and manicured. If the nails aren’t perfect, the solution is often to cover them up with fake nails or polish. But ignoring such signs and viewing them as only an aesthetic problem could be dangerous to your health.

Like your skin, your nails are excellent indicators of what’s going on inside your body. If your nails are healthy (smooth and pink with a slightly curved surface), your body is probably pretty healthy too. But if your nails are discolored, brittle or otherwise appear unhealthy, it may be because of an underlying health problem.

Here are 10 signals your nails may be giving you about your health:

1. Brittle nails: This condition signalizes about iron deficiency, biotin deficiency, kidney disorder, thyroid or circulation problems.

2. Pitting: If you see pits on the nails, it could be a sign that you are about to develop, or that you already have, psoriasis. The small depressions on the nail could also be a sign of chronic dermatitis of your fingers.

3. Clubbing: This condition describes when the nails curve down around the fingertips and the nail bed itself bulges. It’s caused by low oxygen levels in the blood and may indicate lung disease.

4. Spoon Nails: If your nails look scooped out, like a spoon, it could be a sign of iron-deficiency anemia and/or lack of Vitamin B12.

5. Terry’s Nails: In this condition the nails look opaque with a dark band at the tip. This can be due to aging or a more serious illness including cancer, congestive heart failure, diabetes or liver disease.

6. Beau’s Lines: These horizontal indentations across your nails could be a sign of malnutrition. They also may appear after serious injury or illness like a heart attack interrupts the growth of your nail.

7. Nail Separating from Nail Bed: When your nail becomes loose and separates from the nail bed, it could be related to injury, thyroid disease, fungal disease, drug reactions or psoriasis.

8. Brown or Black Colored Streak: This could be a sign of a melanoma under the nail. Melanoma should be suspected whenever a nail streak appears without known injury to the nail, the nail discoloration does not gradually disappear as would a bruise or the size of the nail streak increases over time.

9. White, Crumbly Nails: This is often due to a fungal infection.

10. Small White Spots: These are very common and usually recurring. They’re caused by injury to the base of the nail and are not a cause of concern. The spots will grow out as your nail grows.

The above examples are only some of the ways in which nails indicate about health problems. Although some of the symptoms can appear in healthy individuals as well, an experienced dermatologist can tell if your nails are OK or not. So, if you happen to have some of these symptoms, it is not necessary to panic—just visit a doctor and he or she will tell you if it is serious or not.

Sometimes nails change temporarily in shape and color, or are damaged accidentally (for instance by nail polish), so the fact that your nails look strange to you, mustn’t alarm you. Only if the changes are permanent, then you should take measures. Nails are not a real-time indicator of the health status of the organism because they are the last parts of the body to receive blood and nutrients.

Also, nails tend to absorb various substances, so sometimes different kind of poisoning are still visible on the nails, though the poison itself has been thrown out of the body long ago. Besides, nails grow relatively slow, so the fact that you see lines, or stains, or whatever near the end of the nail, is more related to the past few months, than to the present. But if nails grow damaged from the root, this is an indication of a present unhealthy state of your body.

（來源：英語學習雜志）