1. Bluish nails







Bluish fingernails is a condition that occurs when there isn’t enough  oxygen in your blood. It can happen when your hand is exposed to cold temperatures, which causes your blood vessels to shrink to conserve energy. Once you’re warmed up, the normal color should return again. If the nails remain blue, however, there may be an underlying health disorder that prevents the body from getting enough oxygen through blood circulation. Many different lung problems, heart problems, and blood vessel problems can lead to blue nails.

2. White nails






Having pale or white nails usually means the body is low on red blood cells as a result of not eating well or having a condition that disrupts the normal absorption of nutrients. Diabetes or anemia can also cause white nails.

Nails that are predominately white with only a narrow reddened or dark rim at the top is a condition known as Terry’s nails. Although it can occur with normal aging, Terry’s can also be a warning sign of underlying medical conditions, most notably cirrhosis, chronic kidney disease, and congestive heart failure. In fact, about 80 percent of cirrhosis patients have Terry’s nails.

3. Small white spots







Small white dots appearing on fingernails or toenails is called leukonychia. It’s actually common in healthy adults and is entirely harmless. Leukonychia is usually caused by injuries to the nail bed. These injuries can occur when you shut your fingers in a door or by other forms of blunt trauma. Because of the time it takes for your fingernails to grow out, you may not even recall the exact contact that caused the white spots. As the nail grows, the damaged part will move further up, eventually disappearing.

4. Cracked or split nails






Cracking or splitting of fingernails is more prevalent in women, but men can experience the problem, too. This condition can be associated with various health issues, ranging from thyroid disease to iron-deficiency anemia. Depending on the severity of the condition, you may need to take iron supplements or simply include more iron-rich foods in your diet. Sardines, shellfish, fortified cereals, and liver are all excellent sources of this mineral. If you live an active lifestyle, you may also want to increase your protein intake so that your nails can withstand more friction and trauma.

5. Vertical black lines beneath the nail






One of the most common causes of black discolorations under the nail is trauma, which can cause burst blood vessels underneath the nail. Such injuries usually heal on their own within a few days. More seriously, though, are vertical black lines along the length of the nail, which can be a sign of subungual melanoma—a dangerous form of skin cancer. Typically, these black stripes darken over time, and the affected nail can be painful or even bleed. When accompanied by symptoms like fatigue, fever, or shortness of breath, black lines on nails can be an indicator of endocarditis, a bacterial infection of the heart valves.

6. Yellow nails







When nails turn yellow, it usually means they’re infected by nail fungus. Soaking your hands or feet in hot water mixed with baking soda may prevent fungus from spreading. This is because soda creates an alkaline environment that is hostile to fungus, which can only grow in an environment where the pH is acidic. Add hydrogen peroxide, a common ingredient in whitening toothpaste, for even better color-lightening effects. In rare cases, though, nails that remain yellow despite repeated treatment can indicate thyroid conditions, diabetes, or even skin cancer.

7. White horizontal lines







“Mees’ lines” are horizontal, white lines of discoloration across the nails, a condition that is typically associated with arsenic intoxication. However, Mees’ lines can also be a sign of some other conditions, including kidney and heart failure.

Beau’s lines look similar to Mees’ lines but they are actual ridges instead of discoloration areas. They usually develop when nail plate growth is temporarily disrupted due to injuries, intensive picking at the nails, or inflammatory conditions such as psoriasis. Although there isn’t much you can do with it, Beau’s lines grow out with the nail and will eventually disappear. The complete replacement of a fingernail takes about six months.

8. Beau’s lines






Depressions that run across your fingernail are called Beau’s lines. These can be a sign of malnourishment. Other conditions that cause Beau’s lines are:

  • diseases that cause a high fever such as measles, mumps, and scarlet fever
  • peripheral vascular disease
  • pneumonia
  • uncontrolled diabetes
  • zinc deficiency

9. Spoon nails







A “spoon nail,” as its name suggests, is where the nail becomes concave like a little spoon, and it can sometimes even hold a drop of water. Spoon nails are so thin and soft that the outer edges turn up. The condition is usually associated with iron-deficiency anemia, which is the most common nutritional deficiency disease in the world. It is also seen among people with psoriasis, an autoimmune disease that mainly affects skin. But psoriasis patients typically have other characteristic symptoms such as rashes.

10. Bitten nails






At some point in our lives, we probably have all bitten our nails once or twice. But some people do it much more frequently and compulsively. There can be a million reasons why people bite their nails; some nail biters do it to deal with anxiety; some do it simply because they don’t have better things to do when their minds are elsewhere.

Although unsanitary, nail biting doesn’t necessarily cause serious nail or tooth damage. If you want to kick the habit, you can start by doing something else with your hands when a nail-biting inclination comes on. Whether it is playing with a stress ball, clicking a pen, or twiddling your thumbs, there are actually a lot of things you can do to keep your hands busy and away from your mouth.

11. Vertical ridges






A lot of people have vertical lines running up and down the lengths of their nails. They may also notice these vertical ridges become more numerous and prominent as they age. This happens because aging nails gradually reduce their ability to absorb nutrients and moisture. A fairly common sign of aging, vertical nail ridges are not usually a reason for alarm. However, ridges that occur alongside other symptoms, such as rough or brittle nails, that are not caused by aging may indicate other health conditions. Certain types of anemia, for example, can cause vertical ridges to appear deeper than usual.


12. Clubbing






Clubbing is when your nails thicken and curve around your fingertips, a process that generally takes years. This can be the result of low oxygen in the blood and is associated with:

  • cardiovascular diseases
  • inflammatory bowel disease
  • liver diseases
  • pulmonary diseases
  • AIDS

13. Onycholysis







When the nail plate separates from the nail bed, it causes a white discoloration. This is called onycholysis. This can be due to infection, trauma, or products used on the nails.

Other causes for onycholysis include: