Hypothyroidism, with thyroid hormone deficiency, affects around 2% of the UK population but more than 5% of people aged 60 or over. Women are up to 10 times more likely to be diagnosed with hypothyroidism than men. Unfortunately, if it occurs around the menopause, symptoms can be ignored or misinterpreted, delaying a proper diagnosis.[^7,9]

It is sometimes referred to as an underactive thyroid or myxoedema. The NHS medical exemption certificate in England has the category “myxoedema (that is, hypothyroidism which needs thyroid hormone replacement).”[^5,10]

Primary hypothyroidism relates to thyroid gland conditions, whereas secondary or central hypothyroidism has a pituitary gland or hypothalamus cause. Subclinical or borderline hypothyroidism affects anywhere between 4%-20% of adults.[^7,9]

Typical symptoms relate to decreased metabolism such as fatigue, feeling cold, weight gain, muscle weakness, constipation, dry eyes, dry skin, hair loss, hoarseness, dysmenorrhoea, depression and cognitive impairment.[^4,9,11]

Long-term, hypothyroidism can increase the risk of cardiovascular disease (eg heart failure and hypercholesterolaemia), and osteoporosis. In severe cases, usually affecting older people and where hypothyroidism is left untreated, it can result in myxoedema coma which requires emergency hospital treatment.[^7,11]