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Everyone likes to look their best, and in many cases, how you feel about your appearance can depend on your hair, skin, and nails. Many lotions, supplements, and products promise better hair, skin, and nails, but you can’t get around a basic fact: true health starts from within.
You may associate dull hair, brittle nails, or dry skin with external factors such as swimming in chlorine, harsh soaps, or using the wrong shampoo. Yet, some medical conditions can contribute to your hair, skin, and nail health. An underactive thyroid gland results in hypothyroidism, a medical condition characterized by a low levels of thyroid hormone. Untreated or undertreated hypothyroidism can lead to various problems with your hair, skin, and nail health.
In this article, learn how hypothyroidism affects your hair, skin, and nails and and treatment options to get them back on track.
Your thyroid is a butterfly-shaped gland located at the base of your neck. It produces thyroid hormones -- triiodothyronine (T3) and thyroxine (T4) -- that regulate your body’s energy use and many other essential functions.
These hormones affect virtually every system in the body, including the growth of hair follicles, skin cells, and nail beds. When your thyroid hormone production drops, as seen in those with hypothyroidism, these body processes slow down and change.
Typically, hair follicles regenerate themselves, going through phases of growth, regression, resting, shedding, and then growth again. Research shows that thyroid hormones can directly impact this hair follicle cycling. So, an inadequate thyroid hormone level slows the hair growth cycle.
About 42% of those with hypothyroidism report diffuse hair loss, also known as alopecia. There are three types of alopecia those with hypothyroidism may experience:
- Telogen effluvium: Hair enters the resting phase too early, resulting in partial or diffuse hair loss
- Alopecia areata: Immune-mediated destruction of hair follicles during the growing phase of the hair cycle, resulting in loss of most or all hair
- Madarosis: The loss of eyelashes and hair on the outer third of the eyebrows
Those with hypothyroidism may also have trichodystrophy, characterized by dry, coarse, brittle, and slow-growing hair that easily falls out. Trichodystrophy can also play a role in alopecia, as brittle hair is likelier to fall out.
You may also notice more gray hair popping up. Graying hair can, of course, be due to the natural aging process. Still, it can also be due to hypothyroidism, especially Hashimoto’s thyroiditis, the autoimmune disease that is the primary cause of hypothyroidism in the U.S.
Managing hypothyroidism results in an improvement in hair strength, color, and growth. Upon starting thyroid hormone replacement medications, you may temporarily notice more hair loss as the hair moves from the resting phase to growing.
Those with hypothyroidism may also have trichodystrophy, characterized by dry, coarse, brittle, and slow-growing hair that easily falls out. Trichodystrophy can also play a role in alopecia, as brittle hair is likelier to fall out.
You may also notice more gray hair popping up. Graying hair can, of course, be due to the natural aging process. Still, it can also be due to hypothyroidism, especially Hashimoto’s thyroiditis, the autoimmune disease that is the primary cause of hypothyroidism in the U.S.
Managing hypothyroidism results in an improvement in hair strength, color, and growth. Upon starting thyroid hormone replacement medications, you may temporarily notice more hair loss as the hair moves from the resting phase to growing.
Your skin is the largest organ in your body. It helps protect your body by keeping germs out, holding body fluids in to prevent dehydration, and maintaining your body temperature. Those with untreated or undertreated hypothyroidism may notice changes in their skin.
Dryness
The most common skin disorder in those with hypothyroidism is excessively dry and scaly skin. A 2013 study reported that 65% of participants with hypothyroidism reported having dry skin.
Most often, dry skin is on the outside surfaces of joints and the palms and soles of your arms and legs. Researchers are unclear on what causes dry skin in those with hypothyroidism. Still, they have several theories, such as:
- Low T3 levels promote the thickening of the outer layer of skin (hyperkeratosis), resulting in scaly skin.
- Decreased thyroid hormone levels reduce the production of the protective skin barrier, resulting in dry skin.
- Reduced sweat secretion from sweat glands makes it hard for your body to cool off when it becomes hot, thus causing dry skin.
You can manage dry skin with topical creams, gels, or lotions. However, some skin conditions are severe and need additional treatments.
Skin coloring
Besides dry skin, those with hypothyroidism may experience changes in their skin coloring. The most common skin change is pallor (looking pale).
As thyroid hormone levels drop, so does your metabolism. This results in the narrowing of blood vessels inside your middle skin layer to maintain your core body temperature. As a result, blood flow to your skin decreases, making your skin appear pale. Along those same lines, those with hypothyroidism tend to be anemic, a medical condition that describes a lack of red cells. Anemia can also contribute to a pale appearance in those with hypothyroidism.
There are three other skin conditions those with hypothyroidism may have:
- Vitiligo: An autoimmune disorder that destroys the cells that give your skin its color. As a result, white patches appear on the skin. Those with vitiligo can also have premature graying of their hair. About 25% of those with subclinical or overt hypothyroidism will also have vitiligo.
- Carotenemia: Thyroid hormone is essential for converting carotene to vitamin A. A lack of thyroid limits this conversion, resulting in the buildup of carotene. As a result, those with hypothyroidism may have a yellowish hue to their skin.
- Myxedema: About 10% of hypothyroidism patients may develop waxy, swollen, or doughy skin. Myxedema may also result in facial changes such as swollen lips, puffy eyelids, tongue enlargement, or broadening of the nose. It is unclear what causes these changes, but experts believe TSH causes the activation of cells that secrete collagen proteins. Myxedema typically resolves with thyroid hormone replacement treatment.
Hypothyroidism can significantly impact nail health, with a number of implications, including:
- Brittle nails: Nails may become dry, brittle, and more prone to cracking and splitting due to a slower metabolism and reduced blood flow.
- Slow nail growth: Hypothyroidism can cause nails to grow more slowly because of the reduced rate of cell turnover.
- Ridges and splitting: Vertical ridges on nails may appear, horizontal nail ridges are more common, and splitting of the nail edges can occur more frequently.
- Discoloration: The nail surface may become pale or have a yellowish tint due to reduced blood circulation and changes in nail composition.
- Thickening of the nails: Some individuals with hypothyroidism may experience thickening of the nails, particularly toenails.
- Nail infections: Due to a weakened immune system and poor circulation, individuals with hypothyroidism may be more susceptible to fungal infections in the nails.
- Abnormalities: Hypothyroidism can cause abnormal changes in nail shape or attachment to the nail bed.
A 2023 review on skin disorders in those with hypothyroidism showed that the five most common nail-related symptoms include:
- Increased fragility (70%)
- Slow growth (48%)
- Nail thinning (40%)
- Separation of the nail from the nail bed (onycholysis) (38%)
- Brittleness (13.9%)
The good news is that managing hypothyroidism with optimal thyroid hormone replacement medication is the key to improving hair, skin, and nail health.
Adhering to your thyroid medication regimen and maintaining regular check-ups for blood tests is essential to ensure consistent thyroid hormone levels. A balanced diet rich in fruits, vegetables, and lean proteins provide essential nutrients. Adequate iodine intake, through sources like iodized salt, dairy, and seafood, can support thyroid function. Minerals like selenium and zinc, found in nuts, seeds, and whole grains, are also important, while biotin from eggs, nuts, and whole grains, and omega-3 fatty acids from fish, flaxseeds, and walnuts, contribute to hair, skin, and nail health. Staying hydrated by drinking plenty of water is also important.
Considering supplements like high-quality multivitamins, biotin, and vitamin D can be beneficial, especially if your diet lacks these nutrients. A good skincare routine includes using quality moisturizers to combat dry skin, mild cleansers, and sunscreen for protection. For hair care, gentle, sulfate-free shampoos and conditioners, minimizing heat styling, and regular trims help maintain healthy hair. Nail care involves moisturizing nails and cuticles, wearing protective gloves during chores, and possibly taking biotin supplements to strengthen nails.
Incorporating lifestyle changes such as practicing stress-relieving activities, ensuring adequate sleep, and engaging in regular physical activity can improve circulation and overall health. Consulting a dermatologist or dietitian for personalized recommendations can be beneficial if managing symptoms becomes challenging.
A special note about hair health: After starting thyroid hormone replacement medications, you may temporarily notice more hair loss as the hair moves from the resting phase into the growing phase.
Hair, skin, and nail symptoms don’t necessarily mean that you have an underactive thyroid. But if these symptoms are chronic, it’s wise to test your thyroid so you can understand your next steps and move on to getting effective thyroid treatment to resolve your hypothyroidism symptoms.
Also, when it comes to hair, skin, and nails, remember that patience is required. Improving your hair, skin, and nail health when you’re hypothyroid requires time and consistent management of thyroid levels and overall health.
While many labs only look at thyroid-stimulating hormone (TSH), Paloma Health believes it’s critical also to measure free triiodothyronine (fT3), free thyroxine (fT4), and thyroid peroxidase (TPO) antibodies. These four markers help you understand the bigger picture of what’s happening with your thyroid function and where specifically to make improvements. Paloma’s at-home testing kit allows you to evaluate these four markers from the comfort of your home.
Should your results show that your thyroid is underactive, remember that it‘s a treatable condition. As a Paloma member, you can get thyroid testing and consult with Paloma’s team of thyroid-savvy healthcare providers for virtual visits and thyroid treatment, all from the convenience of home.