I've seen some info online, but can you suggest an authoritative/exhaustive source on what health information, if any, one might gleam from the condition of one's fingernails, i.e., ridges, indents, coloration, spotting, etc.?
You've got the right idea with your question. Nails are not only coverings for the tips of your hands and feet, but they may also be indicators of underlying health issues. Although it's completely normal for nails to look different from one finger or toe to the next, and from one person to the next, abnormalities in your nail(s) might be signs of more serious medical conditions or illness. The Mayo Foundation for Medical Education and Research website contains a slideshow that describes seven different conditions that might be indicated by discolored or atypically shaped nails. These seven conditions, as adapted from and described in detail by the Mayo Clinic, are:
- Yellow nail syndrome: A slightly yellow or green tinge in your nails may mean that you are suffering from some sort of respiratory condition. Two common examples of this are chronic bronchitis or lymphedema, the swelling of your hands. It's not only respiratory diseases that cause the nails to be discolored, however. Anything that can slow nail growth can give nails this appearance. Yellow nail syndrome can also cause the nail(s) to be lacking in cuticles and even become detached from the nail bed.
- Pitting: Pits, or small depressions or dents in the nails, may mean that you are suffering from the skin condition psoriasis. Pitting makes it more likely that your nails will crumble, and is sometimes related to conditions that can also lead to damaged nail cuticles.
- Clubbing: Nails become clubbed when their tips curve around the fingertips, rather than growing straight past your fingers. This usually happens when fingertips become enlarged due to low oxygen levels in the blood. Clubbing may also be an indicator of lung disease, as well as inflammatory bowel disease and liver disease.
- Spoon nails: Spoonnails get their name because they look like the back of a spoon has been pressed on top of them, forming a dip in the nail. This dip is usually large enough to hold a drop of liquid, and can be indicative of iron-deficiency anemia or a condition where your body absorbs too much iron called hemochromatosis. Heart disease and hypothyroidism may also be associated with this nail condition.
- Terry's lines: Also referred to as Terry's nails, most of the nail is opaque, but the tip has a dark band. This may happen simply due to aging, but can also mean a more serious condition, such as congestive heart failure, diabetes, and liver disease.
- Beau's lines: Lines run horizontally across your nails are are a characteristic symptom of Beau's lines, and may appear when cuticle growth is disturbed by an injury or illness. Diabetes, peripheral vascular disease, scarlet fever, measles, mumps, pneumonia, and zinc deficiency are commonly associated with these lines.
- Onycholysis: This refers to the separation of nails from nail bed, which also makes the affected area become white. Many things can cause onycholysis, with the most common cause being physical trauma that causes the nail bed to seperate from the nail. Onycholysis might also be seen in people who have thyroid disease and psoriasis.
Still curious for more? The American Academy of Family Physicians has a guide that provides more information on the conditions described above, as well as pictures, listings and explanations of other nail abnormalities.
Although the descriptions mainly refer to fingernails, toenails can also take on similar appearances. Both can indicate more serious conditions, but its best to consult with your health care provider in order to get a personalized diagnosis. If necessary, a provider can design a specialized treatment plan to get you back on your (hands and) feet (literally!).Alice!