1. Nail pitting
Nail pitting means a small depression in our fingernails; it
is common phenomenon in people who have psoriasis. It can
also be connected to tissue disorders and alopecia.

2. Yellowing, thickening or crumbling
People who have nails which are yellow or whitish, thick and
crumbled, could be a victim of fungal infections.

3. Pale nails
If you nails look lifeless, then it means you have anaemia.
Besides, it can also be a sign of early diabetes or liver disease.

4. Black line
If you notice a black discoloration vertical line, which grows
from the nail bed, then it means that you need to worry
about Melanoma. It usually appears on a single nail and either
shows up on big toe or thumb.

5. Blue nails
If your nails are showing up a bluish tint, then it means that
your body isn’t getting enough oxygen. The reason can be due
to lung infections or some heart problems.

6. Clubbed nails
Nail clubbing means when the tip of your fingers enlarges and
the nails curve around the fingertips. It usually takes years to
form. It also occurs due to low oxygen supply in the body and
indicates sign of various types of lung diseases. It is also a sign
of bowel disease, cardiovascular disease and lung disease.

7. Brittle nails
Dry and brittle nails means you are exposing your nails to
strong chemicals.

8. White lines
If you have white stripes on the entire nail and on more than one
nail, then they are known as Muehrcke’s lines. The reason
behind this problem can be kidney disease, live problems or lack
of protein and other nutrients in the body.

9. Small red lines
Red or brownish red streaks on nails, which looks like dried
blood indicates heart trouble or an ordinary injury.

10. Spoon nails
Spoon nails are soft nails that look hollow. Spoon nails are a
sign of iron deficit or a liver problem.

11.Mee's Line
A single transverse whitish band on the nails seen in arsenic poisoning and renal failure.

Source: www.ynaija.com/top-10-problems-your-nails-can-tell-you/

Muehrcke's line

Mees' line