woman's neck featuring the area of thyroid gland


What is the thyroid gland and what does it do?

The thyroid is a small butterfly-shaped gland located in your neck and it makes two hormones tri-iodothyronine (T3) and thyroxine (T4). These thyroid hormones help your body to use energy, stay warm and keep the heart, brain, muscles, and other organs working as they normally would.
One of the tests to assess thyroid function, is a blood test which measures the hormone called TSH (Thyroid Stimulating Hormone). TSH is made by the pituitary gland (which is in the brain) and its role is to tell the thyroid gland to start making thyroid hormones.

Normally if not enough thyroid hormones are being produced then TSH production increases so that thyroid hormones are released. However, an abnormally high TSH could mean hypothyroidism (underactive thyroid) where not enough thyroid hormones are being produced to keep the body running as it should.

When the thyroid gland doesn’t produce enough of the thyroid hormones many of the body’s functions are slowed down and affected.

The symptoms of an underactive thyroid are non-specific, mild at first and are often put down to other factors such as “getting old”, stress or workload. They can include:

Weight gain

Weight Gain



Cold Tolerance

Irregular Menstrual Periods



Mood Changes

Hair Loss

Puffy Pale Face

Dry Flaky Skin

What Causes an Underactive Thyroid?

An underactive thyroid can be caused by a few different things:

This autoimmune condition causes the body’s immune system to attack and destroy the cells of the thyroid gland. It is the most common cause of underactive thyroid.
Lack of enough iodine in your diet can affect the production of the hormones.
This is when the thyroid is removed, or you might have had radiotherapy that has affected the thyroid gland.
If the pituitary gland is not working properly.
Some medications can affect the production of certain hormones. Your doctor can tell you if any medications are likely to be affecting you.
A number of women will develop an underactive thyroid while they are pregnant or after baby is born. You can learn more about that here.

For many people hypothyroidism is a life-long condition. Your doctor should be able to tell you what has caused it.

Find out more about blood tests and treatment with a tablet called Eltroxin®.