A small butterfly-shaped gland in the neck responsible for producing hormones can create a lot of problems if it is not functioning correctly.
The thyroid gland helps regulate the body's metabolism - the process that turns food into energy - and many of the body's functions can slow down if the amount of hormones produced is lower than normal. It can also produce too many hormones which in turn interfere with the body's systems and cause a whole array of issues.
It can affect both men and women, though it is more common in women and while thyroid conditions are treatable, if they go undiagnosed they can lead to potentially life-threatening episodes. We have had a look at what the NHS lists as the most common signs for both under and over-active thyroids.
