Have you ever felt like something is just… off? Maybe you’re dealing with persistent fatigue, stubborn weight gain, or skin that’s constantly dry, no matter how much you moisturize. There’s a small, butterfly-shaped gland in your neck that could be the culprit, and when it’s not working properly, it can feel like your whole body is falling apart.
This is your thyroid gland, and it’s the master regulator of your metabolism. It produces hormones that control how your body uses energy, affecting nearly every organ. When your thyroid is underactive—a condition called hypothyroidism—this entire system slows down. Millions of people have an underactive thyroid without even knowing it, dismissing their symptoms as normal signs of aging or stress. Today, we’re going to uncover the top 15 signs of hypothyroidism so you know exactly what to watch out for. (Based on the expertise of Dr. Siobhan Deshauer)
👉Key Takeaways
- What it is: Hypothyroidism, or an underactive thyroid, causes a wide range of symptoms affecting everything from your skin and hair to your mood and energy levels.
- Visible Signs: Many signs are visible, such as changes to your skin, hair, and nails, or swelling in your face and neck.
- Hidden Symptoms: Less obvious symptoms include chronic fatigue, intolerance to cold, depression, and unexplained weight gain.
- Diagnosis & Treatment: Diagnosis is made with a simple blood test, and treatment with thyroid hormone replacement is highly effective.
➡️1. An Enlarged Thyroid (Goiter)
One of the most direct signs is a visible change to the thyroid gland itself. Your brain constantly monitors thyroid hormone levels and sends a signal—Thyroid Stimulating Hormone (TSH)—to tell the gland to get to work. If your thyroid is struggling, your brain sends more and more TSH. This constant stimulation can cause the gland to grow in size, creating a swelling at the base of your neck known as a goiter. In severe cases, it can become large enough to make swallowing or even breathing difficult.
➡️2. Dry, Rough, or Cracking Skin
Think of your skin as a brick wall. The cells are the bricks, and a natural mortar made of oils and fats holds them together, locking in moisture. An underactive thyroid dramatically reduces the production of these healthy oils. As a result, moisture escapes, and the wall begins to crack and fall apart. This can lead to extremely dry, rough skin and a distinctive cracking pattern that looks like a mosaic of irregular tiles.
➡️3. Thickened Skin on Hands and Feet
Your skin is constantly shedding and regenerating, a process regulated by thyroid hormones. When those hormones are low, this process is disrupted. Dead skin cells and proteins, particularly a tough protein called keratin, can build up. This can cause a dramatic, excessive thickening of the skin, especially on the palms of your hands and the soles of your feet (a condition called palmar-plantar keratoderma).
➡️4. Hair Loss and Thinning
Keratin makes up 95% of your hair, so it’s no surprise that a thyroid issue has a major impact here. Hypothyroidism disrupts the normal life cycle of your hair. Production slows down, leading to dull, brittle, and thin hair. More distressingly, hair follicles enter their resting phase prematurely, which can lead to massive shedding and diffuse hair loss all over your scalp within a few months.
➡️5. Brittle, Splitting, or Thick Nails
Just like your hair, your nails suffer when growth becomes slow and disorganized. You might notice that your nails become thicker, but the quality is poor, making them prone to splitting and crumbling. Thick vertical ridges can also appear. In some cases, the nail can even begin to separate from the nail bed, a condition called onycholysis.
➡️6. Thinning of the Outer Eyebrows
This is a classic, tell-tale sign of hypothyroidism that doctors specifically look for. Hair loss isn’t just limited to your scalp. You may notice significant thinning of the outer third of your eyebrows. This specific pattern is sometimes called the “Sign of Queen Anne.”
➡️7. Puffy Face and Swelling Under the Eyes
If you notice persistent puffiness, especially around your eyes, it might not be from a lack of sleep. In hypothyroidism, this isn’t just water retention. It’s a buildup of a gelatinous, doughy substance in the skin called myxedema. This substance is part of the scaffolding between your cells, but when you don’t have enough thyroid hormone, it gets overproduced and accumulates.
➡️8. A Swollen Tongue
The myxedema that causes facial puffiness can also build up in your muscles. When it affects your tongue, it can become strikingly large and swollen. This not only feels strange but can also block your airway when you sleep, leading to or worsening obstructive sleep apnea.
➡️9. Numbness and Tingling in Your Hands (Carpal Tunnel Syndrome)
The carpal tunnel is a narrow passage in your wrist that houses the median nerve. The swelling and fluid buildup from myxedema can increase pressure in this tight space, compressing the nerve. This leads to the classic symptoms of carpal tunnel syndrome: numbness, tingling, or pain in your thumb and fingers. A surprising number of carpal tunnel cases are rooted in an undiagnosed thyroid problem.
➡️10. Feeling Cold All the Time
Do you wear a sweater in the summer or socks to bed year-round? While some people just run cold, a persistent intolerance to cold is a hallmark of a slow metabolism. Your cells are running in “low power mode,” performing only the most basic functions and failing to generate the extra energy and heat that come from a healthy metabolic rate.
➡️11. Yellow-Orange Skin (Carotenemia)
Have you noticed an orangey-yellow tint to your skin, especially on your palms and the soles of your feet? This can be caused by a buildup of beta-carotene, the pigment found in foods like carrots and sweet potatoes. Normally, your body converts beta-carotene into vitamin A. In hypothyroidism, the enzyme responsible for this conversion doesn’t work as well, causing the orange pigment to build up in your bloodstream and deposit in your skin.
➡️12. Depression, Brain Fog, and Mood Swings
Your thyroid has a profound impact on your brain. Low thyroid hormones can decrease levels of your feel-good neurotransmitters like serotonin and dopamine. It also reduces activity in the parts of your brain involved in emotional regulation, memory, and motivation. This is why any workup for depression or significant mood changes should always include a blood test to screen for hypothyroidism.
➡️13. Heavy or Irregular Menstrual Cycles
For women, changes to your period can be a major clue. Low thyroid hormone can disrupt the delicate balance of estrogen and progesterone. This hormonal chaos affects your uterine lining, often leading to more buildup, which results in heavier, longer, or more irregular periods.
➡️14. Chronic Fatigue
This is one of the most common symptoms of hypothyroidism, yet it’s also one of the easiest to dismiss. It’s not just feeling tired after a long day; it’s a deep, persistent exhaustion that sleep doesn’t seem to fix. When your body’s metabolism is running at a snail’s pace, profound fatigue is an inevitable result.
➡️15. Unexplained Weight Gain and Constipation
Along with fatigue, these are two of the most frequently cited symptoms. When your metabolism slows, your body burns fewer calories at rest, making it easier to gain weight even if your diet and exercise habits haven’t changed. Similarly, your digestive system slows down, leading to constipation. Because these issues are so common, they are often overlooked as signs of a thyroid problem.
⚙️What to Do Next
If several of these signs sound familiar, don’t panic. The first step is to talk to your doctor. Fortunately, diagnosing hypothyroidism is straightforward. A simple blood test measures your TSH level. If it’s high, it means your brain is yelling at your thyroid to work harder, indicating your gland is underperforming.
The good news is that hypothyroidism is very treatable. The standard treatment is a daily medication called levothyroxine, which is simply a replacement for the hormone your thyroid isn’t making enough of. With proper treatment, many of these symptoms can be dramatically improved or even reversed, helping you get back to feeling like yourself again.
Source: Dr. Siobhan Deshauer