Healthy Lifestyle

What is the thyroid? Your endocrine superstar

A young woman wearing a light gray sweater with her hair in a ponytail resting her head on her arms and smiling. The thyroid affects bodily functions like mood and body temperature.


The small thyroid gland has a big job that affects your energy levels, body weight, mood and more


By Susana Vargas-Pinto, MD, Endocrine Surgery, Nuvance Health


Chances are you have either heard or said, “My thyroid is acting up” at some point in your life — whether from ongoing fatigue, feeling too hot or too cold, or fluctuating body weight. But what exactly does the thyroid do, and when is it actually causing problems?


What does the thyroid do?

The thyroid is the superstar of your endocrine system! Glands make up the endocrine system, which includes all your body’s hormones that regulate how your body functions. The thyroid is a small butterfly-shaped endocrine gland located at the base of your neck. It produces hormones that affect your metabolism — how your body uses energy from food for everything it does, from growing and moving to thinking.


Wait, there’s more! The thyroid plays a crucial role in controlling your:

  • Energy levels
  • Heart rate
  • Breathing
  • Body weight
  • Body temperature
  • Mood
  • Reproductive health


How does the thyroid affect the body?

Now that you know the thyroid has a VIP pass to almost everywhere in your body, you probably want to know the impact it has on your physical and mental health.


When the thyroid is working its magic, you feel energetic, your weight is stable, and your mood is like watching butterflies on a sunny day. You won’t notice your heartbeat, how often you’re taking a breath, or worry about overheating or freezing because the thyroid is working behind the scenes to keep these functions running smoothly.


Even superstars have some blemishes, and sometimes, the thyroid can go a bit haywire. If it decides to take a nap and doesn’t produce enough hormones, your metabolism will slow down. Called hypothyroidism or underactive thyroid, it might feel like your body is stuck in slow motion.


On the flip side, if your thyroid decides to throw a party and releases too many hormones, your metabolism will speed up. Called hyperthyroidism or overactive thyroid, it might feel like you’re on a caffeine high. 


How does the thyroid affect your weight?

Alright, let’s tackle a big myth — is your thyroid making you gain or lose weight? 


While your thyroid has a leading role in your weight, it’s not a one-person show. It’s more as if the thyroid is in an ensemble cast with your diet, activity level, sleep schedule and stress.


Other medical conditions may also cause unintentional weight gain or loss. Heart failure, Cushing’s syndrome, depression, menopause and polycystic ovarian syndrome (PCOS) can cause weight gain. 


Finally, certain medications may affect your weight. For example, some antidepressants and corticosteroids can cause weight gain, and some Type 2 diabetes medications can cause weight loss.


So, how do you know if your thyroid is the main culprit when you are gaining or losing weight? See your doctor to find out if changes in your pounds are unintentional when you’re eating healthily, exercising regularly, getting enough sleep, managing stress, and not on any medications with weight side effects.



What are the signs of problems with your thyroid?

Unchecked thyroid issues can lead to a host of problems, like making your heart work harder than it should or messing with your sleep schedule. 


If your thyroid isn’t working correctly, you may experience the following symptoms depending on the underlying condition. 


Signs of hypothyroidism:

  • Slower heart rate
  • Lingering fatigue
  • Weight gain despite eating well and exercising
  • Feeling cold or more sensitive to cold
  • Joint and muscle pain
  • Mood swings that make you feel out of control
  • Depression
  • For women of reproductive age, heavy or irregular menstrual periods 


Signs of hyperthyroidism:

  • A racing or irregular heartbeat 
  • Unwanted weight loss without trying
  • Digestive health issues, including bowel movements that are more frequent
  • Hand tremors
  • Increased sweating or feeling hot
  • Anxiety and irritability
  • Difficulty sleeping
  • Hair loss
  • For women of reproductive age, lighter or less frequent menstrual periods


Just because you have these symptoms doesn’t mean your thyroid is acting up. Tell your doctor how you’re feeling so they can investigate whether it’s your thyroid or something else through a physical exam and blood draw to test your thyroid function.


Other thyroid conditions include Hashimoto’s thyroiditis and Graves’ disease. Hashimoto’s thyroiditis is an autoimmune condition that can lead to hypothyroidism. On the flip side, Graves’ disease is an autoimmune condition that can lead to hyperthyroidism. 



Should you worry if you have lumps in your thyroid?


Try not to panic if you have a lump in your thyroid. Thyroid lumps or nodules are very common and usually harmless. Oftentimes, they cause no symptoms and are found by accident when someone gets medical imaging of their head or neck for something else. Primary care providers can also feel an enlarged thyroid during a routine physical exam and recommend someone to have follow-up imaging, such as an ultrasound of the neck.


If you have a large thyroid nodule that causes discomfort or pain in the throat or trouble breathing, you may need medical or surgical intervention from an endocrinologist or endocrine surgeon.



Thyroid cancer usually doesn’t cause symptoms in the early stages. Many times, a primary care provider will initiate further studies if they feel a lump or enlarged thyroid during a physical exam. You will need to have a neck ultrasound and biopsy to check if a thyroid lump is cancerous. Learn more: Diagnosed with thyroid cancer? Here’s what to expect


How can you keep your thyroid healthy?

Clearly, the thyroid plays a leading role in your life. Show it some love by:

  • Following an iodine-rich diet: Nourish your thyroid with iodine, found in foods like seafood, dairy and iodized salt.
  • Munching on selenium-rich food: Nuts, seeds and fish have selenium in them, a mineral that helps your thyroid produce hormones.

  • Limiting soy: Whole soy foods such as edamame have many health benefits. But too much soy can affect the thyroid’s hormone production, especially if you’re not getting enough iodine. Follow the serving size guidelines on soy foods to eat them in moderation.

  • Stress less: Easier said than done, we know! But stress can mess with your thyroid. Try yoga, meditation or simply taking a stroll in nature.
  • Doctor dates: Annual physical exams with your primary care provider can keep you aware of any potential thyroid issues and ensure early action if needed.

The bottom line: The thyroid is a multitasking superstar that keeps your body functioning, from your metabolism to emotional health. Many people blame the thyroid for fatigue, and weight and mood changes without really knowing what the thyroid does. This butterfly-shaped gland in the lower neck produces hormones that control how your body uses energy, your heart rate, how you breathe and more. Talk with your doctor if you have symptoms of an underactive or overactive thyroid. If you have thyroid lumps, try not to fret because they are very common and usually harmless.