If you ever go for a dermatologist screening, they’ll request you remove your nail polish. This is also true if you end up in surgery. Why all the hate for polish? Turns out your nails can reveal serious concerns about your health.
A darkened nail can mean a few things, says Dr. Jessica Krant, MD, MPH, a board-certified dermatologist in New York City and founder of Art of Dermatology. First, it could be just a natural, genetic pigmentary change, like a freckle. But if there is a dark streak along the nail from cuticle to tip and there is only one, or it is changing fast, it may mean something more ominous: melanoma of the nail, says Dr. Krant. This is a form of skin cancer and potentially deadly. Some nail fungus infections can also have dark gray or green colors, so when in doubt, see your dermatologist.
Blueish nails are really blueish nail beds, an implication that your fingertips are not receiving enough oxygenated blood, says Dr. Krant. This can be a sign either that your circulation is bad in your hands and feet, or that your lungs aren’t able to properly oxygenate the blood in your whole body, either due to lung disease or heart disease. If you have blue nails, other than for a few brief moment when in very cold weather, see your doctor.
White nails can mean several bad things, but the most serious thing to worry about is liver disease, says Dr. Krant.
Thin, peeling or spoon-shaped (curved concave instead of convex) nails can imply iron-deficiency anemia. This is known as koilonychia, says Dr. Krant.
If you have brittle nails that are hard but break easily, this can be a sign of dryness, or possibly hypothyroidism. Dr. Krant says this is especially true if it goes along with thinning or unusually dry hair.
Longitudinal (Vertical) Ridges
These are usually a normal finding that develops with age. “It’s a sign that the nail matrix (root of the nail under the cuticle) is drying out. Sometimes it’s possible to make it better by keeping extra heavy moisturizing emollients and ointments on the cuticles and nails,” says Dr. Krant.
A deep horizontal ridge with normal nail on either side usually means there was some specific trauma, high stress, illness, or other metabolic disruption for a defined period before the nail went back to growing normally, says Dr. Krant.
Separated from the Nail Bed
A nail detached from the nail bed (onycholysis) can mean nail fungus or infection under the nail, but it may also be caused by certain medications. Either way, see your doctor, says Dr. Krant.
Flattened angle at cuticle
Club-shaped fingertips with broad, flattened nails and cuticle zones are a sign of poor oxygenation of the blood. Clubbing is a common sign in cystic fibrosis in the young, but also in chronic lung disease in the elderly, says Dr. Krant.
Small Indentations or Pits
Small dots or pits in the nail may indicate psoriasis. This can be confined solely to the nails and be relatively harmless, or it may indicate a likelihood of more extensive skin psoriasis or internal psoriatic arthritis. Since psoriasis is linked to a higher risk of heart disease due to chronic inflammation, the nail pits may be a valuable flag, says Dr. Krant.
Not all thickened nails are caused by fungus, which is why it’s important to get a test before starting any risky medication or expensive treatment. Some thickened rough nails are actually caused by psoriasis in a different presentation than the previously mentioned nail pits.
It’s important to keep in mind that even with temporary nail problems that may grow out, fingernails can take six months to fully grow out and toenails up to a year. Knowing this may help you judge how long you’ve had a certain condition and may help link it to an initiating cause. When in doubt, see your dermatologist, Dr. Krant says.