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How winter can affect your thyroid

December 8, 2021 • read

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How winter can affect your thyroid

It’s normal to change your behaviour during the winter months. Less daylight might have you craving more rest and holiday feasting can derail normal eating patterns. It’s not uncommon to put on a couple of pounds and find yourself sleeping more. Seasonal affective disorder can leave some wrestling with depression.

If you have a thyroid disorder, however, you might have trouble distinguishing between cold weather behaviour shifts and your thyroid issues. That’s because many seasonal changes mimic the symptoms of thyroid dysfunction. Here’s everything you need to know about how winter can affect your thyroid.

What’s my thyroid?

Your thyroid is a small gland that sits under the skin, at the front of your neck. It’s shaped like a butterfly and sits in the same place you would wear a bowtie. While small, it does some pretty important work. It’s in charge of your metabolism, which is essentially how your body allocates the energy it gets from food. It does this by producing two major hormones called thyroxine (T4) and triiodothyronine (T3).

What are T3 and T4 hormones?

Triiodothyronine (T3) and thyroxine (T4) hormones do everything from controlling your body’s weight and temperature to regulating your nervous system. These hormones are stored in your thyroid and are released as needed. In certain situations, however, too much or too little T3 or T4 is released. A blood test can reveal if your T3 and/or T4 levels are too high or low, causing a thyroid hormone imbalance.

What are TSH levels and what do they mean?

Your thyroid doesn’t work alone — it relies on your pituitary gland for directions. Your pituitary gland is at the base of your brain, and it activates your thyroid by releasing thyroid-stimulating hormone, or TSH. When your thyroid isn’t working as hard as your body needs it to, your pituitary gland releases more TSH to stimulate it into action. The more active your thyroid, the less TSH will be in your system.

Unless they’re pregnant, most people’s TSH levels fall somewhere within the range of 0.4 milliunits per litre (mU/L) to 4.0 mU/L. If your TSH levels are above 4.0mU/L, you likely have hypothyroidism — also known as underactive thyroid, where your immune system attacks the thyroid gland. Conversely, if your TSH levels fall below the normal range, you could have hyperthyroidism or overactive thyroid.

Symptoms of thyroid issues

The symptoms of thyroid disease aren’t specific. This means the only way of knowing if you have a thyroid condition is through blood testing. These tests can measure your TSH levels, your T3 and T4 production, or thyroid antibodies.

Do thyroid issues get worse in the winter?

Your thyroid is responsible for regulating your body’s temperature. When the cold weather sets in, your pituitary gland sends out more TSH, pushing your thyroid to keep up with your body’s temperature demands. This means that everyone experiences a rise in TSH levels during the winter months, regardless of preexisting issues.

Individuals with hypothyroidism, however, see a slight drop in their T3 and T4 levels during the winter months despite a corresponding rise in their TSH levels. Their thyroid just can’t keep up with their body’s hormonal demands.

T3 and T4 affect many different functions. If you have an underactive thyroid, you may notice an increase in your symptoms during winter. Here are some signs you might be experiencing this.

Increased sensitivity to cold

As the temperature drops, your thyroid has to work harder to keep you warm. If you have hypothyroidism and take medication for it, your regular dose might not be enough come wintertime. If winter brings a chill you can’t shake, speak to your healthcare provider about testing your TSH levels. They might show that it’s time to tweak your medication dosage.

Changes in hair, skin, and nails

Cold air can’t hold onto moisture as well as warm air, so winter air is dry. Add indoor heating to the mix and it can feel like a desert in your home. Those harsh conditions cause the moisture in your skin to evaporate more quickly. As a result, most people wrestle with drier skin and hair during the winter. But dry skin and dry, brittle, or coarse hair are also signs of hypothyroidism.

If you’re experiencing these symptoms, speak to your healthcare team about checking your TSH levels. If these are symptoms of an underactive thyroid, incorporating a thicker moisturizer and adding a humidifier isn’t going to cut it.

Weight gain

With the change in the weather, it’s normal to crave so-called comfort foods, which tend to have higher fat and/or sugar content. Add in the winter holiday season and weight gain can often be the unintended consequence. Weight gain can also be a side-effect of hypothyroidism. If you’ve added a couple of pounds since the arrival of the cold weather and can’t attribute it to a change in behaviour, speak to your healthcare provider.

Feelings of depression

About 15% of Canadians will experience some form of seasonal affective disorder, or SAD, during their life. SAD is a form of depression triggered by a decrease in exposure to sunlight. It can cause you to feel depressed, irritable, lethargic, and more tired than usual. If you have or suspect you have a thyroid disorder, however, these symptoms might also be indicative of thyroid dysfunction.

If you think you may have SAD or a thyroid disorder, speak to your healthcare provider about your changes in mood and energy levels. Both conditions are treatable with a proper diagnosis.

If you have a diagnosis of hypothyroidism, it’s important to consult with a healthcare professional about adjusting your medications during the winter months. An endocrinologist, for example, can determine a medication plan, increasing your dosage slightly in the winter and decreasing it as things warm up. During warmer months, you can also consider baseline testing to see what your normal TSH levels are. While a slight drop in T3 and T4 levels over the winter months might not seem like a huge issue, it can have a major effect on you. Skip the referral and the waiting room and get help from an endocrinologist on Maple today.

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