6 things you need to know about thyroid disorders

Fatigue, irritability and changes in weight: these symptoms are often associated with everything from stress, aging and menopause to poor nutrition, diabetes or depression. However, they're also all symptoms of thyroid disorders, which are commonly overlooked in Canada because their symptoms can be so vague.

In fact, according to The Colorado Thyroid Disease Prevalence Study, more than three million Canadians -- twice as many as who have cancer -- have a thyroid disorder, but about half may not even know it.

Dr. Wendy Rosenthall, an endocrinologist based in Mississauga, Ont., describes the thyroid as "a butterfly-shaped gland sitting on your windpipe on top of your Adam's apple." Its job is to produce hormones that regulate growth, maturation and the speed of your metabolism, but it doesn't always function at the rate it's supposed to, which can cause health problems.

Here are six things you need to know about thyroid disorders:

1. There are two main types of thyroid disorders
Hypothyroidism (underactive thyroid) means a person's thyroid does not produce enough hormones, and that makes their metabolism slow down. About 80 per cent of patients with thyroid disorders suffer from hypothyroidism. 

Hyperthyroidism (overactive thyroid) is less common -- it affects about 20 per cent of people with thyroid disorders. A hyperactive thyroid over-produces hormones and works more than it needs to, speeding up your metabolism.

2. More women suffer from thyroid disorders than men
Women are five to seven times more likely to develop hypothyroidism than men, although it's unclear why. But Dr. Rosenthall warns that anyone can be affected: "It's not confined -- it's a pretty ubiquitous disease," she says.

However, as is the case with many diseases, the incidence of hypothyroidism increases with age. Up to 20 per cent of people aged 60 or older have hypothyroidism and the American Thyroid Association suggests that adults 35 or older be screened for thyroid problems every five years.

3. Symptoms of thyroid disorders are very common
Signs of a thyroid disorder are often very subtle and the most common symptoms -- fatigue, irritability and changes in weight -- are everyday occurrences, so doctors may not look immediately to the thyroid as the source of a problem.

Someone with hypothyroidism may suffer from:
- muscular weakness and constant fatigue
- unexplained weight gain
- moodiness
- muscle aches and pains
- a weak, slow heart beat
- sensitivity to cold
- thick, puffy skin
- forgetfulness
- constipation
- depression
- hoarse voice
- dry skin and hair
- heavy menstrual flow

Dr. Rosenthall says people with hypothyroidism are more prone to depression and "get more of a feeling of sadness" than those with hyperthyroidism, who are more irritable.

Click to continue for symptoms of hyperthyroidism, plus thyroid disorder treatments...

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