Hypothyroidism and Blood Glucose: Understanding the Connection

Table of Contents

Decreases Metabolism

When thyroid hormone levels are low, the body becomes less efficient at breaking down glucose, insulin, and even diabetes medications. As a result, insulin and other glucose-lowering medications may stay active in the body longer than expected, sometimes leading to temporary drops in blood sugar.

Over time, this slowed metabolism can contribute to weight gain, sluggish insulin processing, and insulin resistance, making blood sugar control more difficult. 

People with hypothyroidism may also experience symptoms such as: 

• Fatigue
• Brain fog
• Feeling cold
• Constipation
• Dry skin
• Unexplained weight gain

These are all signs that the body’s energy production and metabolic functions have slowed down.

Impaired Blood Glucose Production

Because hypothyroidism slows the body’s overall metabolism, it reduces the liver’s ability to produce and release glucose during fasting, a process known as gluconeogenesis. It also slows the breakdown of stored glycogen into usable glucose. As a result, the body may struggle to maintain stable blood sugar levels, increasing the risk of hypoglycemic episodes.

At the same time, slowed glucose processing and digestion can make the body less efficient at using insulin and breaking down glucose properly. Over time, this may contribute to insulin resistance, higher fasting blood sugar levels, and difficulty managing Type 2 diabetes. Hypothyroidism can also cause fluctuations between low and high blood sugar readings and may even lead to falsely elevated HbA1c levels.

Hormonal Issues

Hypothyroidism affects hormones by reducing the production of thyroid hormones. When thyroid hormone levels are too low, it can disrupt the balance and activity of several other hormones throughout the body.

Some of the main hormonal effects of hypothyroidism include:



• Cortisol and growth hormone: Hypothyroidism can reduce the body’s ability to release stress hormones that typically help maintain stable blood sugar levels during fasting or episodes of low blood sugar.
• Reproductive hormones: Low thyroid hormone levels can interfere with estrogen, progesterone, and ovulation, which may cause heavy or irregular menstrual periods, fertility problems, or reduced libido.
• Leptin and appetite hormones: Hypothyroidism may alter hormones involved in hunger, fullness, and fat storage, contributing to weight gain and slowed metabolism.
• Adrenal hormones: Thyroid dysfunction can affect the interaction between the thyroid and adrenal glands, influencing energy levels, stress response, and fatigue.

If you’re struggling to manage hypothyroid symptoms, HealthierU is committed to providing natural treatment for hypothyroidism and its effects on your body. Contact Dr. Sergi today to begin your journey to a healthier you.

How Blood Glucose Affects Hypothyroidism

Puts Extra Stress on the Body

Blood sugar instability can place significant stress on the body and raise cortisol levels. When blood glucose repeatedly rises and falls, the body perceives this as a stressor, triggering the adrenal glands to release cortisol and other stress hormones. Over time, chronically elevated cortisol can interfere with thyroid function by suppressing thyroid-stimulating hormone (TSH) from the pituitary gland and reducing the conversion of inactive T4 into active T3. This disruption can slow thyroid activity and contribute to impaired thyroid function.

Increases Inflammation

High blood sugar can contribute to increased inflammation in the body, which may worsen autoimmune conditions such as Hashimoto’s disease. Frequent spikes in blood sugar lead to higher insulin levels, which can promote systemic inflammation. This inflammatory state may intensify immune system activity against the thyroid, further damaging thyroid function. 

Disrupts Hormone Communications

Unstable blood sugar levels can disrupt the body’s hormonal signaling, making it harder to produce, regulate, and effectively use thyroid hormones. At the same time, fluctuating glucose levels can interfere with communication within the pituitary-thyroid axis, impairing normal thyroid regulation.

Taking care of your thyroid and blood sugar health is multi-faceted, requiring a commitment to nutritional health, lifestyle choices, and professional advice. Consider the following strategies and implement them as a way to control hypothyroidism and blood glucose levels. 

#1: Prioritize Nutrition

Eat Balanced Meals

Eating a balanced diet can support both hypothyroidism and blood glucose control by stabilizing energy levels, reducing inflammation, and improving how the body processes insulin and thyroid hormones. Diets such as a low-glycemic load (LGL) or Mediterranean-style eating pattern are especially helpful because they emphasize steady blood sugar and nutrient-rich whole foods.

Key components and foods to include are:

• Proteins: Lean sources like fish, eggs, and legumes to support thyroid hormone production and help stabilize blood sugar
• Healthy fats: Foods like olive oil, avocados, and nuts to support hormone function and slow glucose absorption
• Fiber: From dark leafy greens, like broccoli, zucchini, and asparagus, and whole grains to improve digestion and prevent blood sugar spikes
• Complex carbohydrates: Whole grains such as quinoa, brown rice, and oats to provide steady, slow-releasing energy
• Nutrient-dense foods: Sources of selenium, zinc, and iron to support thyroid health and metabolic function
• Fruits: Berries, apples, and citrus fruits (low-glycemic options that provide antioxidants)

Avoid Processed and Sugary Snacks and Drinks

Limiting processed and sugary foods is important for managing both hypothyroidism and blood glucose because these foods can cause rapid blood sugar spikes and crashes, increase inflammation, and place extra stress on thyroid function. 

Foods to limit or avoid:

• Sugary foods: Candy, baked goods, and desserts
• Sugary drinks: Soda and sweetened beverages
• Refined carbohydrates: White bread, white pasta, and other refined grains
• Processed and inflammatory foods: Margarine, fast food, and highly processed meats

In addition to the foods mentioned in the previous section, some healthier alternatives to replace sugary and processed foods include:

• Nutrient-dense fruits: Berries and other low-glycemic fruits for antioxidants without sharp glucose spikes
• Whole, minimally processed foods: Vegetables, healthy fats like olive oil, and nuts to reduce inflammation and support thyroid health
• Seeds, nuts, and nut butters: Cashews, almonds, macadamia nuts, sunflower seeds, pumpkin seeds, natural peanut butter, almond butter
• Beverages. Water, unsweetened tea, sparkling water

Don’t Skip Meals

Eating regularly helps keep the body balanced and reduces metabolic stress by: 

• Helping prevent blood sugar spikes and crashes
• Lowering inflammation
• Reducing strain on the adrenal glands 

This is important because chronic stress and elevated stress hormones can interfere with thyroid hormone production and the conversion of thyroid hormone into its active form. 

Eating every 3 to 4 hours also helps maintain steady insulin release, giving cells time to respond properly and lowering the risk of insulin resistance. 



If skipping meals has historically been your pattern, try these tips to make regular meals a priority:

• Combine macros (carbs, lean protein, and healthy fat) to help slow glucose absorption and reduce blood sugar spikes.
• Eat a protein-packed breakfast early to regulate insulin efficiency.
• Plan ahead by creating a menu for the week with prescribed meals/snacks throughout the day.

#2: Maintain a Healthy Lifestyle

Exercise Regularly

Regular exercise improves the body’s sensitivity to insulin and helps cells use glucose more efficiently. During physical activity, muscles use glucose as fuel, pulling more sugar from the bloodstream and helping lower blood glucose levels over time. Exercise also increases insulin receptor activity, allowing glucose to move into cells more effectively instead of remaining in the blood. In addition, regular movement may help reduce symptoms associated with insulin resistance and support better hormone balance. 

Gentle to moderate activities such as walking, swimming, and yoga are especially beneficial because they help stabilize cortisol and blood sugar levels without placing excess stress on the body.

Stay Adequately Hydrated

Drinking enough water helps the kidneys remove excess glucose from the bloodstream through urine, which may help maintain healthier blood sugar levels and reduce the risk of hyperglycemia. Proper hydration also supports overall metabolism, energy production, and normal cellular function, all of which are important for thyroid health. 

Choosing water and other non-caloric beverages is best, since sugary drinks can raise blood glucose levels. Adding electrolytes when needed may also help maintain proper hydration balance. A common recommendation is to drink about half your body weight in ounces of water each day; for example, a 150-pound person should aim for at least 75 ounces daily.

Get Enough Quality Sleep

Sleep helps regulate important metabolic hormones, including cortisol, insulin, and growth hormone, all of which influence energy balance and blood sugar control. Poor sleep can raise cortisol levels, disrupt insulin sensitivity, and increase cravings for sugary or high-carbohydrate foods, leading to greater blood sugar fluctuations. 

Sleep also supports the body’s circadian rhythm, which helps the pituitary gland communicate effectively with the thyroid and regulate metabolism. Because thyroid function and blood sugar regulation are closely connected, sleep deprivation can create a cycle in which blood sugar imbalances stress the thyroid, while an underactive thyroid further slows metabolic function. 

Consistently getting 7 to 9 hours of sleep each night can help support healthy hormone balance, metabolism, and overall endocrine function.

#3: Seek Professional Help

Consult a Medical Professional To Manage Lab Work and Medication

Working closely with a healthcare professional is essential for managing both hypothyroidism and blood glucose levels because these conditions can directly affect one another and often require ongoing monitoring and treatment adjustments. 

Your doctor may schedule the following regular bloodwork:

• TSH
• Free T4
• Free T3
• Thyroid antibody tests
• Fasting glucose
• HbA1c
• Insulin levels

The most common medication prescribed for hypothyroidism is Levothyroxine, a synthetic thyroid hormone that replaces the hormone the thyroid can no longer produce adequately. It’s important to follow your doctor’s instructions for taking your medication, which may include:

• Taking it on an empty stomach, 30 to 60 minutes before breakfast
• Not taking it within four hours of calcium, iron supplements, antacids, or certain diabetes medications
• Taking it at the same time each day 

Since thyroid function, blood sugar control, stress, weight changes, diet, and other medications can all influence treatment needs, periodic medication adjustments and follow-up lab testing are often necessary to keep both conditions properly managed.

Utilize Wellness Coaching 

A coach can provide individualized nutrition and lifestyle strategies tailored to support your unique endocrine health needs, like the following:

• Designing anti-inflammatory, balanced nutrition plans 
• Providing personalized strategies tailored to individual endocrine and blood glucose needs
• Helping ensure adequate intake of key nutrients such as selenium, zinc, iodine, and iron
• Supporting gut health and identifying possible food sensitivities or inflammation that may interfere with thyroid hormone conversion
• Using balanced macronutrient strategies, such as pairing carbohydrates with healthy fats and proteins



Recommending complex, high-fiber carbohydrates instead of refined sugars .

HealthierU, led by Dr. Donna Sergi, takes a whole-body approach to wellness by helping clients improve their health through: 

• Personalized nutrition
• Lifestyle guidance
• Natural wellness strategies 

Dr. Sergi focuses on identifying the underlying factors that may be contributing to symptoms such as: 

• Fatigue
• Hormone imbalance
• Digestive concerns
• Thyroid dysfunction
• Stress
• Low energy 

Rather than relying on quick fixes, she works with patients to create sustainable habits that support long-term health and overall well-being.



Patients looking for a more natural and supportive path to better energy, hormone balance, metabolic health, and overall vitality can benefit from the compassionate, personalized care offered at HealthierU.