From the Guidelines
Hypothyroidism presents in several distinct forms, including overt hypothyroidism, subclinical hypothyroidism, myxedema coma, congenital hypothyroidism, Hashimoto's thyroiditis, and drug-induced hypothyroidism, each with characteristic manifestations and requiring prompt diagnosis and appropriate levothyroxine replacement therapy to prevent complications.
Main Forms of Presentation
The main forms of presentation of hypothyroidism include:
- Overt hypothyroidism, characterized by fatigue, cold intolerance, weight gain, dry skin, constipation, bradycardia, and a distinctive facial puffiness, as defined by an elevated TSH level and a low T4 level 1
- Subclinical hypothyroidism, a milder form where patients have elevated TSH but normal free thyroid hormone levels, often with minimal or no symptoms, and can be further classified as having TSH levels between 4.5 and 10.0 mIU/L or greater than 10.0 mIU/L 1
- Myxedema coma, a rare but life-threatening presentation featuring extreme hypothermia, altered mental status, respiratory depression, and cardiovascular collapse, requiring immediate treatment with intravenous levothyroxine 1
- Congenital hypothyroidism, affecting newborns who may show poor feeding, prolonged jaundice, large fontanelles, and if untreated, developmental delays and intellectual disability
- Hashimoto's thyroiditis, an autoimmune condition, often presenting gradually with fatigue, mild depression, and sometimes a painless goiter
- Drug-induced hypothyroidism, which can occur with medications like amiodarone, lithium, or after radioactive iodine therapy
Diagnosis and Management
Diagnosis and management of hypothyroidism involve checking TSH and free T4 levels, with treatment aimed at normalizing these levels and alleviating symptoms 1.
Grading and Management
The management of hypothyroidism can be graded based on the severity of symptoms and TSH levels, with grade 1 being asymptomatic patients with TSH levels between 4.5 and 10 mIU/L, grade 2 being patients with moderate symptoms and TSH levels persistently above 10 mIU/L, and grade 3-4 being patients with severe symptoms or life-threatening consequences, requiring immediate treatment and hospital admission 1. Prompt diagnosis and appropriate levothyroxine replacement therapy are essential for preventing complications and improving quality of life in patients with hypothyroidism.
From the Research
Main Forms of Presentation of Hypothyroidism
The main forms of presentation of hypothyroidism can vary widely, ranging from asymptomatic to life-threatening cases. Some of the most common symptoms include:
- Fatigue and lethargy 2, 3, 4, 5
- Weight gain 2, 3, 4, 5
- Cold intolerance 2, 3, 4, 5
- Constipation 2, 3, 4
- Dry skin 2, 3, 4
- Voice changes 2, 3
Clinical Presentation
The clinical presentation of hypothyroidism can differ with age and sex, among other factors 2. In some cases, the symptoms may be non-specific and overlap with other conditions, making diagnosis more challenging 4.
Severity of Symptoms
The severity of symptoms can range from minimal to life-threatening, with myxedema coma being a rare but severe complication of untreated hypothyroidism 3, 5.
Diagnosis and Treatment
Diagnosis is typically made on biochemical grounds through serum thyroid function tests 5, and treatment usually involves lifelong hormone replacement therapy with synthetic thyroid hormone replacement medication, such as levothyroxine 3, 4, 5.