Slide show: Fingernails — 7 signs of possible health problems

Your fingernails can provide clues to your overall health. But do you know how to read the signs?

Learn about some nail conditions that might require medical attention. If you have a nail problem that doesn't seem to be going away or is associated with other signs and symptoms, make an appointment with your doctor to get it checked out.

Yellow discoloration in your fingernails may result from a respiratory condition, such as chronic bronchitis, or from swelling of your hands (lymphedema). In yellow nail syndrome, nails thicken and new growth slows, resulting in discoloration. Nails affected with this condition may lack a cuticle and may detach from the nail bed in places.

Although this condition is often a sign of respiratory disease, it's possible to have yellow nails and not have a respiratory condition. Yellow nails may also result from any condition that causes the growth of your nails to slow down.

Small depressions in the nails are common in people with psoriasis — a skin condition that produces scaly patches. They may also result from nail injuries. Pitting may cause your nails to crumble.

Pitting is also associated with conditions that can damage your nail's cuticle, such as chronic dermatitis of your fingers or alopecia areata, an autoimmune disease that causes hair loss.

Clubbing occurs when the tips of your fingers enlarge and your nails curve around your fingertips. This condition results from low oxygen levels in your blood and could be a sign of lung disease. Clubbing is also associated with inflammatory bowel disease, cardiovascular disease and liver disease.

Spoon nails (koilonychia) are soft nails that look scooped out. The depression usually is large enough to hold a drop of liquid. Spoon nails may be a sign of iron deficiency anemia.

With the condition known as Terry's nails, your nails look opaque, but the tip has a dark band. Sometimes this can be attributed to aging. In other cases, it can be a sign of serious illness, such as:

• Congestive heart failure
• Diabetes
• Liver disease
• Malnutrition

Beau's lines are indentations that run across your nails. They can appear when growth at the area under your cuticle is interrupted by injury or severe illness. Diseases or illnesses associated with Beau's lines include:

• Uncontrolled diabetes
• Circulatory diseases, such as peripheral artery disease
• Illness associated with a high fever, caused by pneumonia, scarlet fever, mumps or measles
• Malnutrition

With a condition known as onycholysis, your fingernails become loose and can separate from the nail bed. If your nails show signs of detaching, this may be associated with:

• Injury or infection
• Thyroid disease
• Drug reactions
• Reactions to nail hardeners or acrylic nails
• Psoriasis