Your thyroid gland is responsible for a lot of functions in the body, so it's important to address any problems early. The thyroid gland produces hormones which regulate the body's metabolic rate, digestive and heart function, muscle control, brain development and bone maintenance - so the functioning of your thyroid is necessary for all the cells in your body to work normally!

Your thyroid is found in your neck, just below your Adam's apple, and is made up of two lobes joined together by a small bridge of tissue. When your thyroid is normal size, you usually cannot feel it, however if problems develop it can begin to swell.

Thyroid problems are more common in women, with 15 in every 1,000 women affected compared to only 1 in 1,000 men. Experts have suggested that this is because female bodies are more sensitive to hormonal changes.

The two main problems that occur is when the thyroid either becomes overactive or underactive.

Symptoms of an underactive thyroid

An underactive thyroid gland is when the thyroid doesn't produce enough hormones, this condition is more common than an overactive thyroid. An underactive thyroid can be treated with daily hormone replacement tablets. Sadly there is no way of preventing this from happening, as in most cases an underactive thyroid is caused by the immune system attacking the thyroid gland or it may occur through damage to the thyroid gland from other treatments.

Symptoms of an underactive thyroid are often quite general and similar to other conditions, these include:

- Tiredness

- Weight gain

- Depression

- Feeling sensitive to the cold

- Constipation

- Muscle aches

Usually they develop slowly so you may not notice them for a few years, but if you do notice a difference your GP can test your for an underactive thyroid. This test simply involves checking your hormones levels from a sample of blood.

If an underactive thyroid is left untreated symptoms such as a slower heart rate, hoarse voice, puffy face and anemia can occur. It can also lead to complications including heart disease and goitre (a lump at the front of the neck) - so if you notice something usual it's always best to go and talk to your GP.

Symptoms of an overactive thyroid

An overactive thyroid is when the gland produces too many hormones for the body. Excess levels of these hormones can speed up the body's metabolism and lead to a range of symptoms - some of these may include anxiety, hyperactivity, unexplained weight loss and swelling of the gland (usually causing a noticeable lump in the throat).

Problems in the eye area can also be a symptom of an overactive thyroid. Many people don't think twice if they have puffy eyes, because they think it could be due to short-term problems such as a lack of sleep or an allergy. However, puffy eyes can also be a symptom of a problem with your thyroid. Patients with an overactive thyroid can get a thickening of the fat around their eyes - causing them to puff. Other symptoms may also include eye watering, light sensitivity, eyelid swelling and retraction of the eyelid.

There are a variety of ways in which an overactive thyroid can be treated. The most widely used treatments involve medications which stop the thyroid gland producing excess hormones as well as surgery which can remove some of the thyroid gland causing the problem. Sometimes these treatments can result in the thyroid not producing enough hormones - so an underactive thyroid may occur as a consequence.