If You Notice This on Your Nails, Get Your Thyroid Checked, Doctors Say

Whether it's a hang nail or chipped pinky nail, you probably brush most issues with your nails off as nothing more than life's little annoyances. However, if you know where to look, your nails could actually be holding the key to how healthy one vital part of your body is. According to doctors, if you notice something in particular on your nails, you should get your thyroid checked. Read on to find out what you should be looking out for and for more symptoms to pay attention to, If You Feel This at Night, You Need to Get Your Liver Checked, Doctors Say.

If you see white discoloration on your nails, it could be a sign of onycholysis.

Dearbhaile Collins, PhD, a medical doctor at Cork University Hospital, says onycholysis, also referred to as Plummer's nails, is a common medical condition that "occurs when the nails pull away from the nail bed beneath it."

This separation typically results in a white discoloration. While your nail most commonly turns white "due to the presence of air," Collins notes that your nail may also turn brown or green if infected because of onycholysis. And for more on your nails, find out Everything Your Nails Can Tell You About Your Health.

Onycholysis may be an early indication that you have thyroid disease.

A 2019 case review published in The Pan African Medical Journal determined that onychiolysis can be associated with thyroid disease, especially hyperthyroidism. This is a condition in which your thyroid is overactive and produces more thyroid hormones than your body needs, per MedlinePlus. Other symptoms of hyperthyroidism include muscle weakness, rapid and irregular heartbeat, weight loss, and mood swings. "Any unexplained onycholysis should prompt the clinician to investigate the client for asymptomatic hyperthyroidism," the researchers state in the report.

However, Spencer Kroll, MD, a board-certified internal medicine specialist, says that onycholysis may also result from hypothyroidism—which is the opposite condition, where your thyroid is underactive and does not produce enough thyroid hormones for your body. If you also experience "unexpected weight gain, significant fatigue, missed menstrual periods, and hair problems," you should get checked for hypothyroidism, Kroll says. And for more on this vital gland, take a look at the Subtle Signs of a Thyroid Problem Hiding in Plain Sight.

Other nail-related issues may also signal thyroid disease.

Leann Poston, MD, a licensed physician and health expert for Invigor Medical, says that onycholysis is not the only nail issue associated with thyroid disease, however. Besides white discoloration, you may also notice that your nails are thick, dry, and brittle, as well as crumble or break easily.

Your nails may also start to grow more slowly or more quickly than normal, and they could "curve upward due to a swollen fingertip and thickened skin surrounding the nail," Poston says. And for more up-to-date health tips delivered right to your inbox, sign up for our daily newsletter.

Untreated thyroid disease can cause serious complications.

The thyroid gland affects various tissues and organs throughout the body, which means untreated thyroid disease can affect many different parts of your body. Mehmet Oz, MD, a cardiothoracic survey specialist and host of The Dr. Oz Show, says both hyperthyroidism and hypothyroidism can have serious complications if left untreated.

For hyperthyroidism, you may experience more heart problems, "like having a heart rhythm disorder called atrial fibrillation, which increases your risk of stroke and congestive heart failure," he says. You may also be more prone to weakened bones, as well as bulging, red, or swollen eyes. Hyperthyroidism can also lead to "thyroid crisis," which is a rare, but possibly life-threatening condition, Oz says.

Meanwhile, hypothyroidism can also affect the heart and may be associated with an increased risk of heart disease and heart failure. Kroll says that "untreated underactive thyroid disease can also lead to severe depression, decreased mental status, hypothermia, and other symptoms related to the slowing of function in multiple organs." And for more ways to measure your health, If You Can't Do This in 90 Seconds, Your Heart Is in Danger, Study Says.