Hypothyroidism

Ischaemic heart disease - Hypothyroidism Factor

General information

Hypothyroidism is characterised by a reduction in circulating thyroid hormones and is reversible by thyroid hormone replacement therapy so that a normal thyroid state (euthyroid) is attained and hypothyroidism is no longer present.  Subclinical hypothyroidism is an asymptomatic condition which occurs when there are normal levels of thyroid hormone in the blood but a high level of thyroid stimulating hormone (TSH) is detected; this condition is a precursor to hypothyroidism.

Primary hypothyroidism, the most common form, results in a shrunken fibrotic thyroid gland.  Iatrogenic hypothyroidism, following radioactive iodine therapy or surgery for hyperthyroidism, is the second most common form of hypothyroidism.  Drugs used to treat hyperthyroidism (anti-thyroid drugs eg propylthiouracil and methimazole) can cause hypothyroidism, as can drugs containing iodine, such as amiodarone (an anti-arrhythmic drug).  Severe iodine deficiency in certain countries may lead to hypothryoidism.  Secondary and tertiary hypothyroidism are not common and occur when there is disease of the pituitary gland or hypothalamus respectively.

Hypothyroidism is also known as myxoedema.

Signs and symptoms

• fatigue, excessive sleepiness;
• depression;
• dull facial expression, drooping eyelids and slowness of speech;
• cold intolerance;
• weight gain;
• increased cholesterol levels;
• sparse, coarse, dry hair and coarse, scaly, dry, thick skin;
• forgetfulness and decreased concentration with a gradual change in personality;
• puffiness and periorbital swelling;
• cardiomyopathy.

Establishing onset

Onset is subtle and blood testing is required to confirm the diagnosis.  If a person was known to have hypothyroidism this would be recorded in doctors' notes and/or hospital records.  However, if these records have been destroyed or can no longer be obtained and there is a reliable history of hypothyroidism at a particular time, this generally will be accepted, unless there is contradictory evidence.  Obtain medical advice if it is unclear whether the claimed symptoms and treatment at that time can be attributed to hypothyroidism rather than to some other condition.

Last reviewed for CCPS 27 April 2010.

Preliminary questions [9174]

21952 there is some evidence that hypothyroidism may be a factor in the development or worsening of the condition under consideration.

8806     the veteran has had hypothyroidism at some time.

9450     hypothyroidism means a disease state characterised by a reduction in circulating thyroid hormones.

9233     the veteran has established the causal connection between the hypothyroidism and VEA service for ischaemic heart disease.

9234     the veteran had the identified illness or injury, a type of hypothyroidism, before the clinical onset of the condition under consideration.

9236     the veteran has established the causal connection between the hypothyroidism and VEA service for the clinical onset of ischaemic heart disease.

9238     the veteran has established the causal connection between the hypothyroidism and operational service for the clinical onset of ischaemic heart disease.

or

9239     the veteran has established the causal connection between the hypothyroidism and eligible service for the clinical onset of ischaemic heart disease.

or

7334     the clinical onset of the condition under consideration occurred after the end of the veteran's last period of VEA service.

7335     the condition under consideration permanently worsened.

9235     the veteran had the identified illness or injury, a type of hypothyroidism, before the clinical worsening of the condition under consideration.

9237     the veteran has established the causal connection between the hypothyroidism and VEA service for the clinical worsening of ischaemic heart disease.

9240     the veteran has established the causal connection between the hypothyroidism and operational service for the clinical worsening of ischaemic heart disease.

or

9241     the veteran has established the causal connection between the hypothyroidism and eligible service for the clinical worsening of ischaemic heart disease.

Clinical onset and operational service [9238]

8811     the identified illness or injury, a type of hypothyroidism, is causally related to operational service.

Clinical onset and eligible service [9239]

8812     the identified illness or injury, a type of hypothyroidism, is causally related to eligible service.

Clinical worsening and operational service [9240]

8811     the identified illness or injury, a type of hypothyroidism, is causally related to operational service.

9242     the clinical onset of the condition under consideration occurred prior to that part of operational service to which the identified illness or injury, a type of hypothyroidism, is causally related.

Clinical worsening and eligible service [9241]

8812     the identified illness or injury, a type of hypothyroidism, is causally related to eligible service.

9243     the clinical onset of the condition under consideration occurred prior to that part of eligible service to which the identified illness or injury, a type of hypothyroidism, is causally related.