Nail Ailments

How Do Thyroid Problems Affect Toenails?

Every medical condition has its own set of symptoms. Some are invisible to the naked eye, while some are clear signs that something is wrong. The body manifests illness in many ways, and sometimes what’s happening on the outside is a clear sign of something amiss on the inside.

This is especially true for thyroid problems. The thyroid is a small gland in the neck which is responsible for a multitude of bodily functions. These include warming the body, activating the immune system, regulating the metabolism, and controlling the body’s growth.

Some people have an overactive or underactive thyroid gland, which can cause a range of side effects and symptoms. One vital sign that you’re experiencing issues can be seen if you take a look at your toenails. Just like our hair and skin, our nails can be an indicator of an imbalance.

We’re going to explore the effects of thyroid problems on the toenails. We’ll also look at other symptoms and issues that could be responsible.

Can Thyroid Problems Cause Nail Changes?

The short answer is yes. Thyroid problems can affect every element of the body, from your heart rate and temperature to your hair, skin, and nails. The nails are an indicator of when something is off balance in the body. This is why it’s so important to monitor the appearance of your nails.

A Brief Overview of Thyroid Issues

The thyroid is a butterfly-shaped gland which is located just in front of your trachea. It has two main functions: to control growth in early life and to control metabolism. To stimulate these functions, it releases two hormones: thyroxine (T4) and triiodothyronine (T3).

T3 is the hormone that regulates the body’s metabolism. T4 is what’s known as a ‘pro-hormone,’ which means it only becomes active when it is converted to T3 by the body.

There are dozens of factors that affect the thyroid’s function, throwing the production of these hormones out of balance. This then has a knock-on effect on the rest of the body’s functions.

Four main issues can affect the thyroid:

  • Overactive thyroid – also known as hyperthyroidism. This can cause unexpected weight loss, as well as affecting a person’s mood, causing nervousness or hyperactivity.
  • Underactive thyroid – also known as hypothyroidism. This has the opposite effect, causing weight gain and making the sufferer feel tired and depressed.
  • Goitre – this involves a swelling of the thyroid gland, which is usually harmless and fades without further treatment.
  • Thyroid cancer – an uncommon condition that accounts for less than 1% of all cancers diagnosed.

By far the most common thyroid problems are the first two – overactive and underactive thyroids.

Overactive Thyroid

An overactive thyroid produces an excess of thyroid hormones in the body.

These additional hormones circulating the body can cause a range of serious problems, with symptoms including:

  • Difficulty sleeping
  • Nervousness and anxiety
  • Mood swings
  • Swelling in the neck (from the gland itself)
  • Weight loss
  • Palpitations
  • Heat sensitivity
  • Fatigue, tiredness, and weakness
  • Twitching and trembling

Anyone can develop an overactive thyroid, but it’s thought to be around ten times more common in women than men. It’s also most common during the ages of 20 and 40. It can develop in younger and older women, but this is when hyperthyroidism is most likely to start.

How Will Hyperthyroidism Affect My Toenails?

So how does hyperthyroidism affect the toenails? What signs and symptoms might you be looking for to give you a clue about the state of your thyroid?

Hyperthyroidism can cause a condition called Plummers nails. This is when the ends of the nails start to rise away from the nail bed. This condition usually begins on the fourth finger or toe, before spreading to the other nails.

When the nails start to loosen and pull away from the nail bed, it can cause a lot of pain and discomfort. If the nails snag on loose objects, they can pull away entirely, which is enormously distressing.

Plummers nails also mean that dirt can then get under the nails, making them appear unkempt and increasing the likelihood of infections or fungus developing. Fungal nail infections can be very irritating and can cause pain, discomfort and even trouble walking if left untreated.

One specific type of hyperthyroidism is caused by an illness called Graves’ disease. If you have an overactive thyroid caused by Graves’ disease, you might also notice that your nails become thicker and ridged.

This can be confusing because thicker nails are also associated with fungal nail infections – so you may not know whether you’re suffering from an overactive thyroid or a simple infection caused by fungus. If you’re unsure, it’s always best to see a doctor for a proper diagnosis.

Underactive Thyroid

An underactive thyroid (hypothyroidism) doesn’t produce enough of the hormones that the body needs to function. This can lead to a variety of side effects and symptoms as the body attempts to cope with the lack of certain hormones.

These symptoms can include:

  • Tiredness
  • Weight gain
  • Depression
  • Dry skin and hair
  • Aching muscles

As with overactive thyroids, underactive thyroids are more common in women. Just 1 in 1,000 men develops the condition, compared with 15 in every 1,000 women. Congenital hypothyroidism is also possible, with 1 in 4,000 babies born with this condition.

How Will Hypothyroidism Affect My Toenails?

What effect, if any, does hypothyroidism have on the appearance of your toenails? It turns out that having low thyroid function wreaks havoc on your toenails, causing a range of different problems to occur.

Jagged Cuticles – Paronychia

One of the hallmarks of low thyroid function is something called paronychia – or jagged and rough cuticles. Jagged cuticles are often linked with protein deficiencies and tyrosine deficiencies. Tyrosine is an amino acid which is responsible for helping thyroid function, and it’s very common to see those with an underactive thyroid present with both protein and tyrosine deficiencies.

White Ridges

Have you noticed that you see vertical white ridges along your fingernails and toenails? This can be down to a selenium deficiency, which is also linked with low thyroid function. Selenium is crucial in the conversion of T4 to T3 – as we learned before, T4 is inactive until it is converted, so if there’s a lack of selenium in the body, it can lead to not enough T4 being activated and turned into T3.

When our bodies don’t convert T4 to T3 very well, we can start to see signs on our exterior. One of the signs is white ridges on the nails. You might also notice white spots on the toenails signaling a selenium deficiency or underactive thyroid.

Pale Nail Beds

Regular, healthy nails should have a small crescent-shaped white area at the base. If you’re suffering from hypothyroidism, you might notice that the crescent shape gets lighter or disappears entirely. This is because the inadequate protein synthesis caused by hypothyroidism can cause a slowing of the metabolism, which directly affects the nails.

Ingrown Toenails

Hypothyroidism can also cause a range of symptoms that are as of yet unexplained by medicine. One of these is ingrown toenails. Doctors don’t completely understand why those with low thyroid function are more likely to suffer from ingrown toenails – but it’s been observed as a standard feature in many sufferers.

Having an ingrown toenail can be very painful, especially if not treated properly. It can cause problems with mobility, and leave the entire are susceptible to bacterial or fungal nail infections.

Fungal Infections

Speaking of fungus, this is also a common side effect. The thyroid hormone is responsible for the strength of your cardiac contractions. The stronger the contractions, the more blood will make it to your extremities – the fingers and toes, especially.

Without strong enough contractions, the fingers and toes can become cold, and the low oxygen state caused by lack of blood flow can contribute to fungal overgrowth. Fungal nail infections can be unpleasant – they smell foul, they can cause pain and discomfort, and they can be difficult to remove.

If you’re suffering from a fungal infection that you think is the result of hypothyroidism, it’s important that you see a doctor. You can address the fungal infection effectively with a range of over-the-counter treatments, from tea tree oil to medicated creams. But without treating the underlying cause – the underactive thyroid – you run the risk of the fungus coming back over and over again.

How does the thyroid glands affect the nails?

How to Deal with Fungal Infections Caused by Hypothyroidism

As mentioned above, hypothyroidism needs to be addressed with appropriate thyroid medication to prevent fungal nail infections from recurring. But it’s also important to treat the infection itself, to stop it from spreading and start the healing process.

There are many different ways you can treat a fungal toenail infection that’s been caused by an underactive thyroid.

Here are just a few of the options:

Tea Tree Oil

Loaded with antiseptic and antifungal properties, tea tree oil is one of the most potent natural substances you can use to recover from a fungal toenail infection. It’s available cheaply in a multitude of stores, both online and offline – you may even have some lying around your house already.

Tea tree oil can be used in both its diluted and undiluted form. To use it pure, clean the affected toenail and make sure it’s dry. Then, add a few drops of the undiluted tea tree oil to a cotton pad or ball, and apply directly to the nail. It should soak in within around ten minutes. When you notice the nail is dry after the treatment, grab a clean soft-bristle toothbrush (the one you don’t intend to use again!) and gently scrub the affected area.

Some people find pure tea tree oil to be too strong. For those with sensitive skin, it can cause stinging or tingling sensation which some find unpleasant. If this is the case, you can dilute the tea tree oil with another oil, known as a carrier oil. Suitable examples of carrier oils include coconut oil, olive oil or almond oil. Repeat the steps from above to apply it to the affected toenail.

Apple Cider Vinegar

This simple household product is perfect for treating fungal infections that arose from hypothyroidism. It’s a fantastic natural remedy and is used for everything from dry scalps to irritated skin.

You can consume apple cider vinegar internally – it has a multitude of great benefits, from helping to balance gut bacteria to ensure your blood sugar levels don’t fluctuate. But for fighting fungus infections, the topical application of apple cider vinegar is preferred.

Mix one part apple cider vinegar with eight parts warm water. You can also add some Epsom salts to this solution if you have them lying around. Mix the solution in a container that is large enough to accommodate your feet – or the foot that has the infection. Soak your feet in the solution for up to thirty minutes once or twice every day while you’re still suffering from the fungus. This will help to restore your toenails and kill off any bacteria that has lingered.


Did you know this humble mouthwash can be used to kill fungus and restore your toenails to their previously healthy state? It contains ingredients like menthol, eucalyptus, and thymol, which are all great for freshening your breath – but they also have antibacterial and antifungal properties.

Anecdotally, those who have tried this remedy prefer to use the amber-colored Listerine. Simply fill a bowl or basin with the mouthwash and soak your feet for up to thirty minutes each day. Again, feel free to add bath salts or essential oils to the mix, for added fragrance and other benefits.

Toenail changes due to the thyroid glands

Other Tips For Managing Thyroid-Related Toenail Fungus

As well as using the remedies above, here are some top tips to help you recover from a thyroid-related fungal nail infection:

  • Wear clean socks. Change them every day as a rule, and if your feet are particularly warm or sweaty (such as at the gym, or when you get home from work), change them again. Consider wearing antifungal socks.
  • Try to keep the feet as dry as possible. Fungus thrives in moist, warm conditions, so take your shoes off whenever you can, rather than keeping your feet covered up.
  • Fungal infections take a long time to fully heal. The infection is only completely gone when the old toenail has grown out completely. This can take months – be prepared to persevere with your treatment.
  • Be sure to take your thyroid medication as instructed by your doctor. This will help to ensure that you won’t see a returning infection after you’ve worked so hard to treat the first one.
  • Wear flip-flops when using communal spaces such as a swimming pool or a gym. Fungus resides in these locations, and if you have an underactive thyroid, you’ll be extra susceptible to them.

Toenails Are a Reflection of Your Health

The toenails are a great indicator of the state of our internal processes and bodily systems. They can give vital clues as to whether our bodies are suffering from deficiencies in certain vitamins or minerals. They can also flag up conditions like hyperthyroidism or hypothyroidism.

Problems with the thyroid can cause a huge number of symptoms and side effects. Thyroid hormones are responsible for lots of processes within the body, and if we have too little or too much, it can throw the delicate endocrine system out of balance.

It’s important to pay attention to the state of your toenails. They may be covered up for most of the day, but be sure to inspect them regularly. From raised nail beds to white ridges and fungal toenail infections, there are lots of things to keep watching out for if you’re worried about low or high thyroid function. You might also notice pale nail beds, ingrown toenails or jagged cuticles. If you’re worried about anything specific relating to your toenails, it’s always worth seeing your doctor and asking for appropriate tests.