The Ache Behind an Underactive Thyroid

You wake up feeling like you ran a marathon overnight. Your muscles are sore, your body feels stiff, and even simple movements seem to take more effort than usual. You might blame it on a hard workout, a restless night, or simply getting older. But sometimes, the reason is hiding somewhere you wouldn't expect: your thyroid.

An underactive thyroid can affect the body in surprisingly physical ways, including causing muscle aches, stiffness, cramps, and weakness. So how can a tiny gland in your neck leave your muscles feeling sore and heavy? The answer starts with what happens when your thyroid isn't producing enough of the hormones your muscles rely on to function normally.

Learn how hypothyroidism and muscle aches are connected, what’s really causing the pain, and what to do to find relief.

Table of Contents

Yes. Hypothyroidism can cause muscle pain, along with stiffness, cramps, tenderness, and muscle weakness.

When thyroid hormone levels are low, the body's energy metabolism slows, which can affect how muscles produce and use energy. This may lead to:

• Aching or sore muscles
• Muscle stiffness
• Cramps or spasms
• Muscle weakness or heaviness
• Fatigue after physical activity

Muscle symptoms can sometimes be one of the first noticeable effects of an underactive thyroid, but they aren't specific to hypothyroidism. Other conditions, medications, nutritional deficiencies, and overuse may cause similar symptoms.

If muscle pain is persistent or accompanied by significant weakness, it's worth discussing with a healthcare professional and checking thyroid levels. HealthierU offers a holistic approach to hypothyroidism treatment. Contact us today for an initial consultation.

Carnitine is a natural substance that helps turn fat into energy. It is made in the liver and kidneys and stored in the skeletal muscles, heart, and brain. 

In hypothyroidism, changes in metabolism may also affect how muscles produce and use energy. Low levels of carnitine can cause weakness of the muscles in the:

• Hips
• Shoulders
• Upper arms
• Legs

The primary form is caused by a genetic defect and hinders the body’s ability to move carnitine into cells. 

However, several health conditions can cause secondary carnitine deficiency. This form involves low levels of carnitine in the blood and can be treated with carnitine supplementation and avoidance of trigger behaviors, such as:

• Rigorous exercise
• Skipping meals
• Exposure to cold
  

Thyroid hormones play a role in regulating blood glucose levels. In hypothyroidism, changes in thyroid function can disrupt this balance, which may lead to insulin resistance. 

Insulin resistance can result in diabetes if it persists long enough. Studies of the muscles of diabetic patients have shown various abnormalities that include:

• Increased glycolytic fiber numbers
• Muscle atrophy
• Muscle metabolism disturbances
• Muscle weakness
• Decreased muscle plasticity

Skeletal muscle cells lose their insulin responsiveness before other cells, which might explain how prevalent muscle pain is in patients with hypothyroidism. Changes in mitochondrial function have been proposed as contributing to the phenomenon.

Low T4 (thyroxine) can contribute to muscle pain in hypothyroidism because the thyroid hormone is important for normal muscle energy production, metabolism, and repair. When T4 is low, several changes can occur:



• Reduced muscle energy production
• Changes in muscle metabolism
• Abnormal muscle contraction and relaxation
• Changes in muscle fibers
• Possible buildup of muscle-related substances

T4 itself isn’t directly causing the pain. Much of the thyroid’s hormone’s action in tissues occurs through T3, which is produced partly by conversion from T4.

Hypothyroidism-related muscle pain can feel different from person to person, but it’s often described as a dull, persistent ache rather than a sharp pain. Common sensations include:



• Aching or soreness – Muscles may feel tender or as though you’ve overworked them.
• Stiffness – This is more common after waking up or sitting still for a while.
• Heaviness or weakness – Your arms or legs may feel unusually heavy or tired.
• Muscle cramps – Some people experience painful tightening or spasms.
• Tenderness – Muscles may feel uncomfortable when pressed or used.
• Fatigue with activity – Muscles may tire more quickly than usual.

The discomfort can occur in different parts of the body, but the shoulders, thighs, arms, and back are commonly reported areas.

Hypothyroidism can affect the muscles in several ways. Common signs and symptoms include:



• Heaviness in the limbs
• Reduced exercise intolerance
• Muscle fatigue
• Muscle weakness
• Muscle stiffness
• Tender muscles
• Muscle cramps
• Muscle aches and soreness
  

Nonsteroidal anti-inflammatory drugs, or NSAIDs, are commonly used to treat muscle and joint pain. However, if you need something to deal with the pain and discomfort long-term, it may be wise to consider alternative treatment options. NSAIDs can have serious side effects, particularly if taken regularly.

Even in acute pain situations, taking NSAIDs can be counterproductive. They may reduce pain, but they can also interfere with recovery of the muscle that has been injured. In the case of muscle pain caused by hypothyroidism, NSAIDs may wind up inhibiting the removal of injured cells and fail to trigger the rebuilding of healthy ones.

When muscle pain is caused by hypothyroidism, treating the underlying thyroid hormone deficiency is usually the first step. Thyroid hormone replacement medication, most commonly levothyroxine, restores the hormone your body is lacking and helps bring thyroid function back toward a normal range. 

As thyroid hormone levels improve, symptoms such as muscle aches, stiffness, cramps, and weakness may gradually ease. However, improvement isn't always immediate, and it can take several weeks or longer for muscle symptoms to fully resolve. If pain continues despite thyroid levels being well controlled, your healthcare provider may need to look for other possible causes.

The muscle breakdown correlated with hypothyroidism can cause chronic inflammation, which can bring about a whole host of health issues if not addressed. In addition, there are other specific ways hypothyroidism can cause inflammation. All things considered, an anti-inflammatory diet may counteract the chain of events set in motion by hypothyroidism. 

Anti-inflammatory diets have been found to reduce pain in patients who suffer from fibromyalgia, rheumatoid arthritis, and osteoarthritis, all of which are chronic conditions that cause muscle pain.

Eating a nutrient-dense diet low in carbohydrates may help reduce inflammation. Consider foods like:

• Fruits
• Green, leafy vegetables
• Whole grains
• Healthy fats
• Foods rich in probiotics and prebiotics
  

Although it may initially seem like a bad idea, working the affected muscles can help them stay healthier and minimize the damage they sustain from hypothyroidism. Gentle, low-impact aerobic exercises can help maintain muscular efficiency as well as combat depression, weight gain, and fatigue. 

Consider activities like:

• Swimming
• Walking
• Stationary cycling
• Jogging 

To learn more about natural treatment for hypothyroidism, contact HealthierU today.

Muscle pain alone cannot confirm hypothyroidism. A healthcare professional may consider symptoms, medical history, medications, and blood tests such as TSH and free T4, along with other possible causes of muscle pain. If you’re dealing with muscle pain from hypothyroidism, or other hypothyroidism-related symptoms, speaking with HealthierU can help.

Often, yes. Treating the underlying thyroid hormone deficiency can improve muscle-related symptoms, although recovery may take time. Persistent symptoms may have another cause and should be evaluated.

If muscle pain is persistent, unexplained, worsening, or accompanied by significant weakness or other concerning symptoms, it’s time to seek professional healthcare.

If hypothyroidism is leaving you with persistent muscle aches, stiffness, or fatigue, you don’t have to accept these symptoms as part of your everyday life. Addressing thyroid health alongside nutrition, exercise, and other lifestyle factors may help support your overall well-being and get your hypothyroidism under control. 

At HealthierU, we take a personalized approach, using nutrition and lifestyle support, to help people better understand and manage their thyroid-related symptoms. If you’re ready to take a closer look at your thyroid health, we offer a complimentary consultation to get you started.

Don’t live in pain. Contact HealthierU today.