Could This Hormone Condition Be Why You're Gaining Weight?


Free People

When women talk, the conversation can sometimes turn to the thyroid or thyroid symptoms. A lot gets attributed to this little hormone-producing gland—weight gain, feeling the cold and even hair loss are often blamed on the thyroid. But is it really this that's causing your problems, and what even is our thyroid actually for? If you’ve ever thought that perhaps your health problems could be thyroid-related, then keep reading. We’ve called on our resident aesthetic doctor and GP, Jane Leonard, MD, to reveal everything you need to know about thyroid symptoms.

Keep scrolling to dispel the myths and get to the truth once and for all.

What are hormones?

The best place to start when discussing thyroid symptoms is with hormones. Hormones are best described as chemical messengers that are produced by the glands of the endocrine system. Secreted into the bloodstream, they control major bodily functions from fertility and hunger to emotions and mood, so they are pretty darn important! There are many hormone-producing glands that make up the endocrine system, and they all have very different roles. This month we’re turning our attention to the thyroid gland, which is a butterfly-shaped endocrine gland that is found in the centre of your neck.

What does the thyroid gland do?

It produces and secretes hormones, which control your metabolism (the rate your body breaks down food into energy which burns calories to produce energy). The hormones involved in this process are T4, thyroxine, and T3, triiodothyronine.

Thyroid Conditions:

This term simply describes thyroid swelling. It can be benign and cause no health problems at all. In some cases, the swelling of the thyroid gland can occur secondary to a medical condition affecting the thyroid gland, such as iodine deficiency or inflammation caused by infection or autoimmune disease.

More commonly when people talk about hormone deficiency or hormone imbalance related to the thyroid gland, they are referring to two conditions: underactive thyroid disease known as hypothyroidism, or overactive thyroid disease known as hyperthyroidism. Both can be diagnosed with a simple blood test through your GP.

thyroid conditions:

Hypothyroidism is more common than hyperthyroidism, and it is more common in women than men. An underactive thyroid gland results in reduced production of thyroid hormones. The result is a reduced metabolic rate that leads to the following symptoms:

  • Tiredness
  • Weight gain
  • Inability to lose weight
  • Aches and pains
  • Feeling the cold more than normal
  • Dry skin
  • Thinning hair
  • Fluid retention
  • Low mood

Less common symptoms include:

  • Irregular periods
  • Infertility
  • Loss of libido
  • Reduced memory
  • Carpel tunnel syndrome

What causes hypothyroidism?

In the UK, the most common cause is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. In this condition, the body’s own immune system attacks the cells of the thyroid gland. The cells are damaged, which means they cannot produce enough thyroid hormones to meet the needs of the body, and the symptoms of hypothyroidism develop.

Another cause can be treatments to correct hyperthyroidism, which can often result in reduced production of thyroid hormones leading to hypothyroidism. It’s a tricky balancing act. 

Iodine deficiency can affect thyroid hormone production. Good food sources of iodine include eggs, fish, milk and sea vegetables like kelp, so eat up or try an iodine supplement.

thyroid conditions:


Hyperthyroidism occurs when the thyroid gland produces excessive levels of thyroid hormones into the blood. Toxic levels of thyroid hormones can lead to more serious symptoms referred to as thyrotoxicosis.

The symptoms of hyperthyroidism include:

  • Restlessness
  • Anxiety
  • Poor sleep, unable to settle
  • Palpitations
  • Racing heart beat
  • Reduced appetite
  • Weight loss
  • Sweating
  • Cannot tolerate warm/hot temperatures
  • Diarrhoea
  • Shortness of breath
  • Swollen thyroid gland
  • Eye discomfort

This also affects women more than men (just our luck!).

What causes hyperthyroidism?

Similar to hypothyroidism, hyperthyroidism is mostly commonly caused by an autoimmune disease known as Graves disease. This typically affects woman aged 20 to 50 years and is more common in people who have a family history or thyroid disease or a family history of other autoimmune diseases, such as diabetes or rheumatoid arteritis.

In autoimmune diseases, the body’s immune system produces antibodies, known as autoantibodies, which attack the normal, healthy cells of the body. In Graves disease, the immune system produces autoantibodies that target the cells of the thyroid gland to stimulate it to produce and release excessive levels of thyroid hormones.

Another cause can be thyroid nodules, which are lumps that develop on the thyroid gland that can put your thyroid hormones out of whack.


For both over- and underactive thyroid, a simple blood test can diagnose the problem. Treatments include medication with regular blood tests to monitor your thyroid production.


  • The thyroid gland is an endocrine gland found in the neck.
  • It produces thyroid hormones T4 and T3.
  • Thyroid hormones are produced in response to another hormone called the thyroid-stimulating hormone released from the pituitary gland.
  • Thyroid hormones control the body’s metabolism.
  • Thyroid hormone imbalances lead to two conditions: HYPOthyroidism and HYPERthyroidism.
  • Both conditions have “opposite” symptoms and effects on metabolism.
  • If you experience any of the symptoms discussed, do not ignore them. You should see your doctor who will be able to offer tests and treatment options.

Next up: Is this why you're tired all the time?