Definition of Hypothyroidism:
A Clinical condition characterized by subnormal level of circulating thyroid hormones. It associated with generalized non pitting ordema is called myxocdema.
Classification of Hypothyroidism:
1. Primary: Here the abnormality is within thyroid gland, either structural or functional.
2. Secondary: Here the abnormality is in the hypothalamic-pituitary axis resulting in decreased production of TSH.
In another classification:
Goitrous: Associated with enlargement of thyroid gland.
Nongoitrous: Not associated with enlargement of thyroid gland.
Causes of Hypothyroidism:
- Hashimoto’s thyroiditis,
- Spontaneous atrophic hypothyroidism,
- Graves’ disease with TSH receptor-blocking antibodies.
2. latrogenic :
- Radioactive iodine ablation,
- Drugs : Lithium, Carbimazole, methimazole, propylthiouracil , Amiodarone.
3. Transient thyroiditis:
- Subacute (de Quervain’s) thyroiditis,
- Post-partum thyroiditis.
4. Iodine deficiency: e.g. In mountainous regions
- Thyroid aplasia.
- Riedel’s thyroiditis,
- Sarcoidosis etc.
7. Secondary hypothyroidism: TSH deficiency
Management of Hypothyroidism:
Clinical feature of Hypothyroidism:
- Increased sensitivity to cold,
- Dry skin,
- Weight gain,
- Puffy face,
- Muscle weakness,
- Elevated blood cholesterol level,
- Muscle aches, tenderness and stiffness,
- Pain, stiffness or swelling in your joints,
- Heavier than normal or irregular menstrual periods,
- Thinning hair,
- Slowed heart rate,
- Impaired memory.
Investigation of Hypothyroidism:
1. Thyroid function tests:
- Total T4 & T3: T4 & T3 – decreased,
- TSH- increased,
- Free T4 & T3 – decreased.
2. Antithyroid antibodies:
- Antimicrosomal /peroxidaseAb,
- Antithyroglobulin ab.
3. Thyroid scan, USG, FNAC.
4. Routine exam: Rx:
- CBC- Anaemia,
- Serum cholesterol & TG : Raised,
- Urine R/M/E,
- X- ray chest : Cardiomegaly,
- ECG (>40 yrs): Low boltage ECG,
- X-ray neck lateral and A/P view V Retrosternal extension,
- Serum Na+ level: – decreased,
- Serum enzymes: Raised AST, CK & LDH.
1. Oral thyroxin single dose/day.
- 50 ug0.05 mg daily & then increased,
- 1st 3 wks -50 µg once daily,
- 2nd 3 wks – 100 µg once daily,
- Lifelong — 150 µg once daily.
Hypothyroidism with IHD: Start with low dose such as 25 µg day.
2. If rapid response is required, tri-iodothyronine 20 µg 3 times daily.
Regular thyroid function test -6 weekly & adjust thyroxin dose.
Once the dose of thyroxin is established – thyroid function test-1-2 yearly.
Difference Between Hypothyroidism and Hyperthyroidism:
Points of Difference
Also known as over active thyroid.
Also known as underactive thyroid.
Most Common Cause
Graves’ disease, also
Thyroiditis, too much
Less common. Roughly
More common. Nearly
Weight loss but
Weight gain but loss
Warm and moist
Dry and coarse
Fine and soft
Thin and brittle
Maria Khatun Mona is a Founder and Editor of Nursing Exercise Blog. She is a Nursing and Midwifery Expert. Currently she is working as a Registered Nurse at Evercare Hospital, Dhaka, Bangladesh. She has great passion in writing different articles on Nursing and Midwifery. Mail her at “[email protected]”